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SURGICAL  AND  MECHANICAL 

TREATMENT  OF 

PERIPHERAL  NERVES 


By 

BYRON  STOOKEY,  A.  M.,  M.  D. 

Associate   in   Neurology,   Columbia  University, 

Assistant  Surgeon,  New  York  Neurological   Institute, 

Assistant  Professor  of  Neurosurgery,  New  \'ork  Post-Graduate  Medical  School  and  Hospital 


With  a  Chapter  on 

NERVE  DEGENERATION  AND  REGENERATION 

By 
G.  CARL  HUBER,  M.  D. 

Professor  of  Anatomy  and  Director  of  Anatomical  Laboratories,  University  of  Michigan 


WITH  TWO  HUNDRED  AND  SEVENTEEN  ILLUSTRATIONS 
EIGHT  IN  COLOR,  AND  TWENTY  CHARTS 


PHILADELPHIA  AND  LONDON 

W.   B.  SAUNDERS  COMPANY 

1922 


<\)i'YHi(;iiT.   WH'Z,  BY  W.  B.  Saunders  Company 


>1ADE    IN     U.    S.    A. 


Biomedical 
LikniT 


TO   THE   MEMORY 

OF 

MY    FATHER 

DR.  LYMAN  POLK  STOOKEY 

WHO   INSPIRED   MY   LIFE'S    WORK 

THIS  VOLUME    IS 

LOVINGLY   DEDICATED 


577762 


PREFACE 

No  surgical  treatment  of  peripheral  nerves  can  be  intelligently  undertakne 
without  an  eye  on  their  anatomical  and  physiological  connections  with  the 
central  nervous  system.  Nerves  cannot  be  considered  as  independent  peri- 
pheral structures,  as  are  muscles  and  tendons,  but  rather  as  peripheral  parts  of 
the  central  nervous  system,  in  close  association  and  intimate  relation  with  the 
latter.  The  surgical  treatment  of  peripheral  nerves  is  closely  allied  to  the 
surgery  of  the  brain  and  spinal  cord  and  forms  the  third  division  of  the  surgery 
of  the  nervous  system,  \^'hile  the  brain  and  spinal  cord  have  received  great 
attention  the  peripheral  nerves  have  been  singularly  neglected  and  surgical 
practices  have  been  evolved  ill  adapted  to  nerves,  their  special  histology  and 
special  manner  of  repair.  An  attempt  has  been  made  to  examine  critically 
and  make  use  of  researches  and  investigations  in  the  anatomy  and  physiology 
of  peripheral  nerves  which  have  a  direct  bearing  on  their  treatment  and  should 
form  a  basis  for  it.  In  the  first  number  of  the  Archives  of  Surgery  Dr.  William 
Mayo  has  aptly  said  that  "The  philosophy  of  surgery  has  lagged  and  opera- 
tions based  on  unsupported  opinions  as  to  their  wisdom  or  necessity  are  too 
frequently  advocated."  If  this  be  true  for  general  surgery  it  is  more  particu- 
larly true  for  peripheral  nerve  surgery  where  methods  have  been  employed 
without  sufficient  regard  for  the  embryology,  anatomy,  physiology  or  clinical 
indications. 

The  aim  of  this  book  has  been  to  give  principles  and  methods  whose 
foundations  are  laid  in  embryology,  anatomy,  and  physiology  as  well  as  in 
experimental  work,  and  in  clinical  practice,  and  to  advocate  the  use  only  of 
such  procedures  as  have  been  shown  by  such  criteria  to  be  of  value.  It  is  not 
sufficient  to  be  famihar  with  the  gross  anatomy  alone,  for  the  microscopic 
anatomy  must  also  be  pictured.  In  peripheral  nerve  surgery  it  is,  perhaps,  this 
particular  phase  which  is  especially  needed  and  has  been  too  often  wanting. 
The  technic  of  nerve  surgery  is  the  more  successful  the  nearer  it  approaches 
what  might  be  termed  histological  surgery.  Considerable  attention  has  been 
given  to  the  fallacies  of  certain  practices  in  nerve  surgery  and  it  is  hoped  that 
these  have  been  shown  sufficiently  to  indicate  their  futihty  and  to  warrant  the 
author's  contention  that  they  be  discarded.     Stress  at  times  has  been  placed  on 

9 


I  o  PREFACE 

the  coini)arative  anatomy  and  embryology,  for  only  by  an  understanding  of 
these  can  a  broad  conception  of  peripheral  nerves  and  their  surgery  be  gained. 

The  more  general  neurological  aspects  of  peripheral  nerves,  including  the 
various  syndromes,  motor,  electrical  and  sensory  have  been  so  admirably  treated 
by  Tinel  and  Anasthasio-Benisty  that  no  attempt  has  been  made  to  parallel 
these  excellent  works;  but  rather  to  present  the  surgical  and  mechanical  phases 
of  peripheral  nerves,  barely  treated  by  these  authors.  The  motor  changes  in 
nerve  injuries  which  underlie  the  various  deformities  are  dealt  with  so  that  intel- 
ligent mechanical  treatment  may  be  undertaken.  The  importance  of  measures 
other  than  surgery  has  been  emphasized  for  they  are  felt  to  be  essential  for  a 
successful  outcome  of  any  purely  surgical  measure.  IVIost  of  these  principles 
the  author  was  privileged  to  learn  while  temporary  assistant  during  1915-1Q16 
to  Sir  Robert  Jones,  whose  teachings  it  is  agreed  are  so  fundamentally  sound. 
Nerve  crossing  in  anterior  poliomyelitis  has  not  been  dealt  with  since  the 
author  does  not  advocate  its  use. 

I  feel  particularly  honored  to  have  the  chapter  on  "Nerve  Degeneration 
and  Regeneration"  written  by  Dr.  G.  Carl  Huber,  Professor  of  Anatomy,  Uni- 
versity of  Micliigan,  whose  brilliant  researches  in  peripheral  nerves  in  1895 
and  since  have  been  epoch  making.  It  was  a  distinct  pleasure  to  have  had  the 
opportunity  to  work  with  him  during  part  of  his  latter  experimental  work  and  to 
have  gained  from  him  an  experimental  basis  for  the  study  of  peripheral  nerves. 

I  wish  to  express  my  gratitude  to  Dr.  Louis  Casamajor,  Department  of 
Neurology,  Columbia  University,  for  his  encouragement,  his  constant  aid  in 
reading  the  manuscript,  his  many  critical  suggestions  and  valuable  corrections. 
By  his  splendid  assistance  he  has  placed  me  in  his  debt. 

It  is  a  pleasure  to  express  my  appreciation  to  Dr.  Frederick  Tilney,  Dr. 
Oliver  S.  Strong,  and  Dr.  Charles  A.  Elsberg,  Department  of  Neurology, 
Columbia  University,  whose  teachings  in  neurology  and  neurosurgery  have 
been  a  constant  source  of  profit  and  pleasure.  I  am  under  further  obligation 
to  Dr.  Elsberg  for  his  aid  in  the  preparation  of  the  manuscript,  and  to  my 
brother.  Dr.  Lyman  Brumbaugh  Stookey,  for  many  valuable  criticisms  and 
suggestions. 

I  wish  to  acknowledge  free  use  of  Cunningham's  Anatomy,  Testut  and 
Jacob's  Traite  D'Anatomie,  Streeter's  article  in  Keibel  and  Mall,  articles  of 
Alfred  S.  Taylor  on  Brachial  Plexus  Injuries,  and  articles  of  my  own  published 
in  Surgery,  Gynecology  and  Obstetrics;  Archives  of  Neurology;  New  York 
State  IMedical  Journal;  Journal  of  the  American  Medical  Association;  and  the 
Neurological  Bulletin,  which  have  formed  the  basis  of  several  chapters. 


PREFACE  .  II 

I  am  glad  to  thank  Miss  Salome  Slingluff  for  her  cooperation  and   skill 

in  interpretation  in  making  the  illustrations,  and  Miss  Etta  R.  Schamberg  for 

her  willingness  and  painstaking  work  with  the  manuscript,  and  the  publishers 

Messrs.  Saunders  Company  for  their  interest  and  valuable  cooperation  in  many 

details. 

Byron  Stookey. 
515   Park  Avenue, 
New  York  Citv. 


CONTENTS 


CHAPTER  I 

Page 
Anatouv J  J 

Formation  of  Ventral  and  Dorsal  Roots — Ventral  and  Dorsal  Primary  Divisions — Com- 
parative Anatomy — Motor  and  Sensory  Components  Distinct — Formation  of  Mixed 
Nerve — Early  Intermingling  of  Nerve  Fibers — Histology: — Neuraxis — MeduUated  and 
Non-medullated  Fibers — Nerve  Trunk: — Development — Formation  of  Ganglionic  Crest — 
Cellular  Changes  in  Ganglionic  Crest — Formation  of  Primitive  Dorsal  Root — Segmentation 
of  Ganglionic  Crest — Formation  of  Ventral  Root — Migration  of  Sheath  Cells — Origin  of 
the  Neuraxis — Migration  of  the  Sympathetic  Cells — Formation  of  the  Gray  and  White 
Rami  Communicantes — Theoretical  Importance  of  Funicular  Anatomy — Evidence  not 
in  Support  of  Stoffel's  View — Definite  Funicular  Arrangement  Only  in  Restricted  Portions 
of  the  Nerve  Trunk — Results  of  Dissection  of  Macerated  Specimens — Funicular  Identifica- 
tion by  Bi-polar  Stimulation — Limitations  of  Bi-polar  Stimulation — Internal  Nerve  Plexuses 
— Axial  Rotation. 

CHAPTER  II 

Nerve  Degeneration  and  Regeneration 41 

Historical — Modern  Methods — Experimental  Embryology — Modern  Staining  Methods — 
Monogenetic  and  Autogenetic  Theories  of  Regeneration — Experimental  Evidence  Supports 
Monogenetic  Theory — Degeneration  of  MeduUated  Nerve  Fibers — Degeneration  of  Non- 
medullated  Fibers — Degeneration  of  Nerve  Endings  in  Muscle — Changes  at  the  Point  of 
Injury — Abortive  Regeneration — Behavior  and  Fate  of  the  Neurolemma  Sheath — Regenera- 
tion of  a  Peripheral  Nerve — Secondary  Hole  of  the  Sheath  Cell — Doubtful  Chemotactic 
Influence — Selectivity  of  Motor  or  Sensory  Regenerating  Fibers  not  Found — Formation  of 
the  Medullary  Sheaths  and  Neurolemma — Nerve  Transplantation — Fresh  Transplants — 
Preserved  Transplants — Heterotransplants. 

CHAPTER  III 

Methods  of  Nerve  Repair 80 

Standardization  of  Terms — Use  of  Specific  Terms  Recommended — Methods  to  be  Dis- 
carded— Nerve  Flap,  Technical  Considerations,  Experimental  Results — Suture  a  Distance, 
Histological  Basis  of  Method — Nerve  Implantation,  Critic  of  the  Method,  Its  Value — 
Methods  Available: — End-to-end  Suture,  Funicular  Suture — The  Ideal  Suture — Nerve 
Crossing,  Correspondence  in  Function  Essential,  Dissociation  of  Associated  Movements 
Desirable — Nerve  Transplantation,  Clinical  Results,  Experimental  Results,  Failure  Possibly 
Due  to  Technical  Faults  in  Suture,  Re-exploration  of  Graft  Indicated — Preserved  Grafts — 
Methods  to  Diminish  Nerve  Gaps: — Mobilization  of  Nerve  Ends — Importance  of  Wide 
Exposure — Nerve  Stretching,  Limitations  and  Dangers — Two  Stage  Operation — Trans- 
position, Advantages  and  Uses — Resection  of  Bone. 

CHAPTER  IV 

Direct  Nerve  Implantation  and  Direct  MtJscuLAR  Implantation 112 

Direct  Nerve  Implantation  in  Human  Surgery — Experimental  Evidence  in  Support  of 
Method — Hyperneurotization — Direct  Muscle  Implantation  in  Human  Surgery — Experi- 
mental Evidence  in  Support  of  JNIethod — Further  Experimental  and  Clinical  Studies 
Needed. 

13 


14  CONTENTS 

CHAPTER  V 

Page 
TUBULIZATION 121 

Tubular  Suture  Offers  a  Single  Large  Path  tor  Uowngrowing  Xeuraxes — Tubulization  as  a 
Jleans  of  Nerve  Isolation — Decalcified  Bone  Tubes,  Disadvantages — Hardened  Arteries, 
Importance  of  Elastic  Layer — Technic  of  Arterial  Tubulization — The  Use  of  Fresh  Blood 
Vessels — Implantation  into  Veins  In  Situ — Magnesium  Tubes — Gelatine  Tubes — Galalith 
Tubes — Agar  Tubes — Rubber  Tubes — Objection  to  Certain  Jlethods — Facial  Tubuliza- 
tion, Limitations,  Dangers — Cargile  Membrane — Iluber's  Alcoholized  Cargile  Membrane. 


CHAPTER  VI 

Nerve  Liberation 130 

Inhibition  of  Nerve  Conductivity  Without  Destruction  of  Nerve  Fiber — Sources  of  Nerve 
Pressure — Nerve  Concussion — Electric  Examination  of  Nerve  Trunk — Injection  of  Salt 
Solution  as  a  Means  of  Internal  Liberation — Nerve  Liberation  vs.  Nerve  Suture — Technic 
of  Nerve  Liberation — Results. 


CHAPTER  MI 

Technic  of  Nerve  Suture 136 

Position  of  the  Patient — Suture  Materials — Instruments — Anesthetic — General  Operative 
Technic — Special  Incisions — The  Skin  Incision — Nerve  Stretching — Level  of  Suture — 
Technic  of  End-to-end  Suture — Technic  of  Nerve  Crossing — Partial  Nerve  Crossing — 
Technic  of  Nerve  Graft. 


CHAPTER  VIII 

Indications  for  Operation  and  the  Time  to  Operate — C.-vuses  of  Failure 157 

Value  of  Complete  History — Local  Examination — Importance  of  Data  Obtained  by  Local 
Examination — Sensory  Examination — Discussion  of  Terms — Technic  of  E.xamination, 
Limitations — Returning  Sensation — Relation  of  Non-medullated  Fibers  to  Pain  and 
Temperature — Motor  Examination — Importance  of  Individual  iluscle  Action — Electric 
Examination — Longitudinal  Reaction — Polar  Equality — Reaction  of  Complete  Degenera- 
tion— Importance  of  Electric  Examination — Diagnostic  Value — Signs  of  Regeneration — 
Neokinetic  and  Paleokinetic  Fibers  in  Peripheral  Nerves — Functional  Differences  of 
Sarcoplasm  and  Sarcostyles — Tinel's  Sign,  Its  Limitations — Time  of  Regeneration  Follow- 
ing Suture — Interrupted  Regeneration  and  Reoperation — Criteria  for  Estimating  Results 
of  Nerve  Suture,  Time  of  Operation — Regeneration  Without  Operation — Early  Nerve 
Exploration — Value  of  Knowing  Anatomical  Field — Limitations  of  Nerve  Exploration — 
Advantages  of  Early  Operation — Factors  Interfering  with  Successful  Regeneration — 
Importance  of  Proprioceptive  Impulses — Muscular  Reeducation. 


CHAPTER  IX 

Mechanical  Treatment 183 

Importance  of  Treatment  Other  than  Operative — Purpose  of  Mechanical  Treatment — 
Effect  of  Over-stretching  as  Seen  Clinically — Experimental  Evidence — Changes  in  Dencrv- 
ated  Muscle — Fetal  Muscular  Differentiation  Independent  of  Nerve  Supply — Value  of 
Mechanical  Treatment — The  Ideal  Apparatus — Early  Mechanical  Treatment — Late 
Mechanical  Treatment — Time  to  Change  Position  of  Extremity  after  Operation — .\sso- 
ciated  Treatment,  Massage,  Electricity  and  Baths — Electrical  Treatment — Method  of 
Lapicque — Treatment  During  Stage  of  Recovery — Reeducation. 


CONTENTS  15 

CHAPTER  X 

Page 

Facial  Nerve 197 

Importance  of  Facial  Musculature — Experimental  Facial  Nerve  Crossing — Spinofacial 
Crossing — Hypoglossofacial  Crcssing — Advantages  of  Hypoglossofacial  Suture — Ana- 
tomical and  Physiological  Considerations — Embryological  Development  of  the  Hypo- 
glossal Xerve  and  the  Dcscendens  Hypogiossi — Operative  Indications — Traumatic  Injuries 
— Bell's  Palsy — Congenital  Mal-development  of  Facial  Nerve — Operative  Technique — 
Exposure  of  Facial  Nerve — Exposure  of  Spinal  Accessory  Nerve — Hypoglossofacial  Suture 
— Exposure  of  Hypoglossal  Nerve — Technic  of  Implantation — Mechanical  Treatment. 

CHAPTER  XI 

Brachial  Plexus 220 

Relation  of  the  Brachial  Plexus  to  the  Development  of  the  Upper  Extremity — Embryology 
of  the  Brachial  Plexus — Anatomical  Consideration  of  the  Brachial  Plexus — Motor  Root 
Supply  to  the  Muscles  of  the  Upper  Extremity — Post-fixed  and  Pre-fixed  Types  of  Plexus — 
Anatomical  Types  of  Brachial  Plexus  Injuries — Mechanism  of  Shoulder  Girdle  Move- 
ments— Upper  Radicular,  Duchenne-Erb  Type  of  Injury,  Deformity,  Mechanical  Treat- 
ment— Middle  Radicular  Injury — Lower  Radicular  or  Duchenne-Aran  Tj'pe,  Mechanical 
Treatment — Obstetrical  Paralysis — Etiology — Secondary  Injury  of  the  Spinal  Cord — 
Pathology — Mechanical  Treatment — Deformity — Duration  of  Treatment — Late  Mechani- 
cal Treatment — Reeducation — Exercises — Time  of  Operation — Operative  Technic — 
Surgical  Treatment  in  Neglected  Cases — Brachial  Plexus  Injuries  in  Adults,  Pathology, 
Treatment — Cervical  Rib — Probable  Cause  of  Late  Appearance  of  Symptoms — Deformity 
— Cause  of  Vascular  Disturbances — Sensory  Changes — Mechanical  Treatment — Surgical 
Treatment. 

CHAPTER  XII 

MUSCULOSPIRAL    AND    CIRCUMFLEX    NeRVES 265 

Anatomy — Course — Variations  in  Course — Branches — Terminal  Branches — Xerve  Plexuses 
Anomalies  in  Distribution — Deformity  in  Complete  Injuries  of  Dorsal  Cord,  Mechanical 
Treatment — Deformity  in  Musculospiral  Nerve  Injuries,  Mechanical  Treatment — Disso- 
ciated Paralysis  of  the  Musculospiral  Nerve — Exposure — Position  of  the  .Xrm — Incision — 
Exposure  in  the  Arm — Special  Incisions — Perpendicular  Course  of  the  Nerve — Exposure 
of  the  Posterior  Interosseous  Nerve — Transposition  of  the  Musculospiral  Nerve — Comment 
— Circumflex  Nerve — Course — Branches — Exposure  in  the  .Vxilla — Exposure  at  the 
Surgical  Neck — Deformity — Mechanical  Treatment. 

CHAPTER  XIII 

MfSCULOCUTANEOUS    NeRVE 302 

Anatomy — Course — Branches — Anomalies  of  the  Musculocutaneous  and  Median  Nerves — 
Varieties  of  Communications — Deformity,  Mechanical  Treatment — Exposure  in  the  .\xilla 
— Exposure  of  Secondary  Cords  of  the  Brachial  Plexus — Exposure  of  the  Musculocutaneous 
in  the  .\rm — Comment. 

CHAPTER  XIV 

.Median-  Nerve 3i6 

.Vnatomy — Course — Variations  in  Formation  and  Course — Branches — Motor  Branches, 
Lower  Part  of  the  .\rm,  Forearm,  Wrist — .Anomalies  of  the  Median  and  Ulnar  Nerves — 
Varieties  of  Communications — Clinical  Evidence  of  Communications — Deformity,  Mechani- 
cal Treatment — Exposure  of  the  Median  Nerve — Position  of  the  .\rm — Incision — 
E.xposure  at  the  Elbow — E.xposure  at  the  Wrist — Comment. 


l6  CONTENTS 

CHAPTER  XV 

Page 

Ulnar  Nerve 347 

Anatomy — Course — Branches — Funicular  Anatomy — Deformity,  Mechanical  Treatment — 
Exposure  of  the  Ulnar  Nerve  in  the  Arm — Position  of  the  Patient — Incision — Exposure  at 
the  Elbow — Incision — Exposure  in  the  Forearm — Exposure  at  the  Wrist — Injuries  Asso- 
ciated with  Fracture  of  Medial  Condyle — Comment. 

CHAPTER  XVI 

LUMBO-SACRAL    PlEXUS 372 

Embryological  Development — Relation  to  Development  of  Lower  Limb — Torsion  of 
Lower  Limb — Variations  in  Segmental  Distribution — Pre-fixed  and  Post-fixed  Varieties — 
Injury  to  the  Lumbo-sacral  Plexus. 

CHAPTER  XVII 

Sciatic  Nerve 377 

Anatomy — Course — Branches — Funicular  Anatomy  of  the  Peroneal  Division — Funicular 
Anatomy  of  the  Tibial  Division — Exposure  of  the  Sciatic  Nerve — Position  of  the  Patient — 
Exposure  of  the  Upper  Third — Exposure  in  the  Thigh — Exposure  in  the  Popliteal  Space — 
Exposure  of  the  Tibial  Nerve — Exposure  of  the  Internal  and  External  Plantar  Nerves — 
Exposure  of  the  Peroneal  Ncrs'e — Transposition  of  Peroneal  Nerve — Deformity  in  Sciatic 
Nerve  Injuries — Mechanical  Treatment — Comment. 

CHAPTER  XVIII 

Nerves  Infrequently  Injured  4ig 

Recurrent  Laryngeal  Nerve; — Suture — Direct  Implantation — Etiological  Factors  in 
Recurrent  Laryngeal  Paralysis — Spinal  Accessory  Nerve: — Syndrome  of  the  Foramen 
Lacerum — Anatomy — Course — Variations — Deformity — Mechanical  Treatment — Expo- 
sure— Long  Thoracic  Nerve ; — Anatomy — Deformity — Mechanical  Treatment — Exposure — 
Suprascapular  Nerve : — Anatomy — Deformity — Mechanical  Treatment — Exposure — 
Anterior  Crural  Nerve: — Surgical  Treatment — Deformity — Mechanical  Treatment — 
Obturator  Nerve: — Exposure — Deformity — Superior  and  Inferior  Gluteal  Nerves: — 
Exposure. 

CHAPTER  XIX 

Nerve  Tumors 433 

Neuroma — Fibroma — Location — Origin — Relation  to  Neuraxes — Treatment — Plexiform 
Neurofibroma — Malignant  Degeneration — Frequency — Differentiation  Between  Primary 
and  Secondary  Malignancy — Genesis — Primary  Neurosarcoma — Metastasis — Treatment — 
Neuroblastoma. 

CHAPTER  XX 

Causalgia 445 

Early  Use  of  Alcohol  in  Facial  Nerve — Selective  Action  on  Sensory  Fibers — Use  of  Alcohol 
in  Nerve  Irritation — Role  of  Sympathetic  in  Causalgia — Perivascular  Sympathetectomy — 
Anatomical  Basis  of  Perivascular  Sympathetectomy — Ligature  of  the  Nerve  in  Causalgia. 

CHAPTER  XXI 

Amputation  Neuroma 456 

Painful  Amputation  Stump  may  be  Due  to  Causes  Other  than  Nerve  Bulbs — Varieties  of 
Painful  Neuroma — Infected  Neuroma — Histology  of  Neuroma — Relation  of  Regenerating 
Neuraxes  to  Connective  Tissue  Proliferation — Treatment  by  Injection  of  Alcohol — Method 
of  Closure  of  the  Nerve  End. 

Index 463     ' 


1 


SURGICAL  AND  MECHANICAL  TREATMENT  OF 
PERIPHERAL  NERVES 

CHAPTER  I 

ANATOMY  OF  THE  SPINAL  NERVE 

GROSS  ANATOMY 

A  typical  peripheral  nerve  is  made  up  of  neuraxes  from  nerve  cells  either 
within  the  brain  stem  and  spinal  cord,  or  from  cells  of  the  spinal,  cranial  and 
sympathetic  ganglia.  If  a  nerve  contains  processes  only  from  motor  cells  of  the 
brain  stem  or  cord  it  is  known  as  an  efferent  or  motor  nerve,  and  if  processes 
only  from  sensory  cells,  an  afferent  or  sensory  nerve.  Rarely  can  this  absolute 
distinction  be  made;  even  in  so-called  pure  motor  nerves  some  afferent  proprio- 
ceptive fibers  may  be  present  as  well  as  sympathetic  postganglionic  fibers  to 
glands,  etc.  Mixed  nerves,  which  constitute  the  great  majority  of  peripheral 
nerves,  contain  axones  of  motor  cells  of  the  brain  stem  or  spinal  cord  as  well  as 
processes  of  the  cranial  or  spinal,  and  sympathetic  ganglia. 

From  the  distal  part  of  the  spinal  ganglia  fibers  are  seen  to  pass  laterally 
and  are  joined  very  shortly  by  fibers  from  nerve  cells  in  the  basal  or  ventral 
part  of  the  spinal  cord.  These  two  bands  unite  to  form  a  typical  spinal  nerve. 
The  fibers  which  pass  central  from  the  ganglia  form  the  dorsal  root  and  those 
from  the  basal,  or  ventral  part  of  the  spinal  cord,  the  ventral  root. 

Almost  immediately  after  the  union  of  the  dorsal  and  ventral  roots,  which 
usually  takes  place  within  the  intervertebral  foramina,  the  spinal  nerve  divides 
into  ventral  and  dorsal  primary  divisions.  The  dorsal  primary  division  passes 
backward  to  supply  the  dorsal  axial  musculature,  the  skin  over  these  muscles 
and  it  extends  also  to  the  skin  in  the  region  of  the  skull  and  onto  the  axio- 
appendicular  junctions  of  the  upper  and  lower  extremities.  The  ventral 
primary  division,  after  contributing  fibers  to  the  sympathetic  through  the 
white  ramus  communicans,  passes  lateroventrad  to  supply,  by  means  of  lateral 
and  ventral  branches,  the  lateral  and  ventral  axial  musculature  and  the  skin 
over  them.  (See  Fig.  i.)  By  rearrangement  of  the  ventral  primary  divisions 
into  ventral  and  dorsal  secondary  divisions  plexuses  for  the  supply  of  the  struc- 
tures of  the  extremities  are  formed  at  the  level  of  the  axio-appendicular  junc- 
tions of   the  upper  and  lower  extremities.     The  dorsal  secondary'  divisions 

17 


1 8  SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 

correspond  to  the  lateral  branch  of  a  typical  spinal  nerve  and  the  secondary 
ventral  to  the  ventral  branch. 


Lateral  branch 


Ventral  branch 


Fig.  I. — Schematic  drawing  of  a  typical  spinal  nerve.  The  fibers  which  form  the  peripheral 
part  of  the  nerve  are  indicated  but  are  not  carried  throughout  the  nerve.  These  fibers  are  the 
axones  of  motor  cells  situated  in  the  ventral  gray,  a;  Peripheral  processes  of  sensory  cells  in  the 
dorsal  ganglion,  b;  and  sympathetic  fibers,  through  the  gray  ramus  communicans,  c.  The  primary 
ventral  division,  colored  green,  is  that  part  of  the  typical  spinal  nerve  which  enters  into  the  forma- 
tion of  the  limb  plexuses.  The  lateral  branch  becomes  the  dorsal  division  of  the  plexus  and  the 
ventral  the  ventral  division. 

COMPARATIVE  ANATOMY 

The  motor  and  sensory  components  of  the  spinal  nerves  in  some  of  the  lower 
forms,  as  the  Amphioxus  and  Petromyzon,  remain  as  separate  motor  and  sensory 
nerves  throughout  their  course  and  have  no  connections  with  each  other. 
Each  nerve  arises  from  the  spinal  cord  at  different  segmental  levels  for  each 
corresponding  nerve — the  motor  opposite  each  muscle  plate  and  the  sensory  at 
the  intermuscular  septum.     (See  Fig.  2.) 

The  sensory  fibers  are  collected  into  two  branches,  ventral  and  dorsal,  which 
unite  a  short  distance  from  the  cord  to  form  the  dorsal  root.     The  sensory 


ANATOMY    OF    THK    SPINAL   NERVE 


19 


ganglion  cells  are  scattered  throughout  both  the  ventral  and  dorsal  sensory 
branches  and  in  the  dorsal  root,  thus  recalling  the  diffuse  arrangement  of  the 
sensory  cells  found  in  some  of  the  invertebrates.  (See  Fig.  3.)  According  to 
Allen's  (1917)   studies  of  the  adult  Polistotrema  the  ventral  sensory  and  the 


Fig.  2. — Graphic  reconstruction  of  two  spinal  nerves  from  an  adult  Amphioxus.  Observe  that 
the  motor  and  sensory  components  are  widely  separated  and  that  the  ganglion  cells  are  scattered 
through  the  sensory  rami  and  the  dorsal  root.  The  light  area  immediately  outside  the  motor  rami, 
bordered  by  a  dotted  line,  is  taken  to  be  fibrous  connective  tissue.  X  50.  (Allen,  Jour,  of  Comp. 
Neur.,  191 7).  V.R.,  Ventral  root  (radix  posterior);  R.D.  M.,  ramus  dorsalis  or  posterior  (motor); 
R.D.S.,  ramus  dorsalis  or  posterior  (sensory);  D.R.,  dorsal  root;  A'.C,  nerve  cell;  R.  V.T.,  ramus  ven- 
trahs  or  anterior  (sensory);  Sp.Cd.,  spinal  cord;  R.V.M.,  ramus  ventralis  or  anterior  (motor); 
Nc,  notocord. 


;*p.C<(. 


Mu. 


Fig.  3. — Transverse  section  passing  through  the  dorsal  root  and  ramus  ventraUs  from  an  adult 
Amphioxus.  Note  the  ganglion  cells  scattered  through  the  dorsal  root,  ramus  ventralis  and  dorso- 
lateral portion  of  the  spinal  cord.  X  50.  (Allen,  Jour,  of  Comp.  Neur.,  191 7.)  NC,  nerve  cell; 
Myo.,  myotomes;  R.V.S.,  ramus  ventralis  or  anterior  sensory;  D  R.,  dorsal  root  (radix  posterior); 
Sp.Cd.,  spinal  cord. 

ventral  motor  branches  are  united,  forming  a  mixed  nerve,  the  first  to  appear 
in  the  vertebrate  series,  whereas  the  dorsal  sensory  and  the  dorsal  motor 
nerves  still  remain  as  separate  and  distinct  nerves  having  no  connection  with 
each  other.  In  the  most  caudal  sensory  nerves — the  caudal  series  being  always 
less  advanced  ontogenetically  than  the  cephalic — the  sensory  ganglion  cells 


20  SURGICAL   AND    MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 


DMy. 


R.D.Mt 


Fig.  4. — Graphic  reconstruction  of  a  spinal  nerve  and  the  vagus  trunk  from  an  adult  Polisto- 
trema  series  in  the  neighborhood  of  the  caudal  extremity  of  the  retractor  mandibuL-e  muscles.  It  is 
clear  from  this  figure:  (i)  That  the  dorsal  motor  and  sensory  nerves  are  separate.  (2)  The  ventral 
motor  nerve  joins  the  ventral  sensory  nerve  opposite  the  notochord  to  form  a  mixed  ramus  ventralis. 
(3)  .\n  isolated  peripheral  ganglion  cell  appears  in  the  ramus  ventralis  about  on  a  level  with  the 
ventral  border  of  the  myotomes.     (4)  The  vagus  nerve  is  here  divided  into  three  or  four  large  bundles, 


ANATOMY    OF    THE    SPINAL    NERVE  21 

are  scattered  along  the  course  of  the  sensory  nerves  in  both  the  ventral  and 
dorsal  branches,  thus  repeating  the  conditions  found  in  the  Amphioxus  and 
Petromyzon. 

Each  of  the  ventral  roots  of  the  motor  nerves  of  the  Polistotrema  arises  by  a 
series  of  small  rootlets  arranged  in  two  groups,  cephalic  and  caudal,  having 
separate  foramina  of  exit.  The  cephalic  group  gives  rise,  in  the  main,  to  the 
ventral  motor  division,  and  the  caudal,  to  the  dorsal  motor  division. 

In  the  embryological  development  of  Polistotrema  the  same  primitive  condi- 
tions as  found  in  Amphioxus  and  Petromyzon  are  repeated,  in  that  the  ventral 
and  dorsal  motor  branches  are  separate  throughout  their  entire  course.  The 
more  cephalic  motor  root  appears  earlier  than  the  caudal,  and  since  the 
cephalic  group  of  motor  rootlets  contributes  mainly  to  the  ventral  branch 
and  the  caudal  group  to  the  dorsal,  it  might  be,  as  Allen  has  suggested,  that 
the  ventral  branch  phylogenetically  is  older  than  the  dorsal.  This  view  receives 
additional  support  from  the  fact  that  the  ventral  branches  of  the  motor  and 
sensory  nerves  unite  to  form  a  mixed  nerve — a  more  advanced  condition — while 
the  dorsal  motor  and  dorsal  sensory  nerves  remain  separate.     (See  Fig.  4.) 

In  the  adult  shark  the  spinal  nerves,  while  having  some  differences  in  their 
segmental  arrangement  from  the  above,  are  mixed  sensory  and  motor  nerves 
both  in  the  dorsal  and  ventral  divisions,  whereas  in  the  early  stages  of  the  shark 
embrj'o  the  sensory  and  motor  nerves  are  separate.  In  some  of  the  later 
embryonic  stages  they  remain  separate  in  part  of  their  course;  the  sensory  and 
motor  parts  of  the  dorsal  divisions  are  still  separate,  while  the  sensory  motor  and 
parts  of  the  ventral  division  have  united  to  form  a  single  mixed  nerve,  thus 
showing  the  later  development  of  both  the  dorsal  sensory  and  dorsal  motor 
nerves.  At  first  the  motor  and  sensory  fibers  do  not  mingle  to  form  a  true  mixed 
nerve.  The  afferent  and  efferent  neuraxes  merely  run  in  two  adjacent  bundles, 
separated  by  a  layer  of  neurolemma  cells,  and  only  in  their  more  distant  por- 


and  since  all  of  these  bundles  possess  nerve  cells  they  all  probably  contain  sensory  or  receptive  fibers. 
(5)  These  cells  are  sufficiently  numerous  in  the  ventral  bundle  to  form  an  elongated  ganglion  about  a 
segment  long,  and  any  section  through  it  would  reveal  from  one  or  two  to  fourteen  cells.  (6)  ,\11  of 
the  fibers  to  the  cesophagus,  both  sensory  and  motor,  come  from  this  ventral  bundle.  X  11.  (.\llen, 
Jour,  of  Comp.  Neur.,  191 7.)  D.Myo.,  dorsal  border  of  myotomes;  Z>./?.,  dorsal  root  (radix  posterior) ; 
M.C.P.  (i),  posterior  division  of  the  M.  constrictor  pharyngis;  Nc,  notochord;  N.C.,  nerve 
cell;  Ocs.,  oesophagus  or  pharynx;  R.D.M.,  ramus  dorsalis  or  posterior  (motor);  R.D.S.,  ramus  dor- 
salis  or  posterior  (sensory) ;  R. M.C.P.  (i),  vagus  branches  to  posterior  division  of  the  M.  constrictor 
pharyngis.  R.Ocs.,  vagus  branches  to  cesophagus  or  pharynx;  J?. F.,  ramus  ventralis  or  anterior; 
R.V.M.,  ramus  ventralis  or  anterior  (motor);  R.V.S.,  ramus  ventralis  or  anterior  (sensory);  Sp.Cd., 
spinal  cord;  Sp.G.,  spinal  ganghon;  V.Myo.,  ventral  border  of  myotomes;  V.R.  (r),  cephalic  ventral 
or  anterior  root;  V.R.  (2),  caudal  ventral  or  anterior  root;  X.,  vagus  nerve. 


2  2  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


tions  are  these  fibers  intermingled  forming  a  mixed  motor  and  sensory  nerve. 
This  point  is  noteworthy  in  its  relation  to  the  early  development  and  first 
appearance  of  what  has  been  called  the  funicular  anatomy  or  internal  top- 


Neuraxis. 


Medullary  sheath. 


Nucleus  of  neurolemma. 


Motor  ending. 


Dendrite. 


Collateral  branch. 
Neurolemma. 


Node  of  Ranvier. 

segment. 


Axis-cylinder  of  medullated  nerve-fiber . 


-  —    Muscle-fibers. 


Fig.  5. — Diagram  of  peripheral  motor  neurone.     (Bohm,  Davido£f,  and  Huber.) 

ography  of  the  peripheral  nerve.  It  is  significant  that  at  this  early  period 
phylogenetically  the  afferent  and  efferent  bundles  retain  their  individuality  only 
for  an  extremely  short  time,  and  that  when  united  there  is  soon  complete 
intermingling  of  the  fibers. 

HISTOLOGY 

The  neuraxis  consists  of  a  slender,  protoplasmic  outgrowth  from  a  ganglion 
cell,  extending,  without  interruption,  from  the  cell  of  origin  to  its  ultimate 


ANATOMY    OF    THE    SPINAL    NERVE 


23 


termination,  though  it  may  give  off  numerous  collaterals  in  its  course.  (See 
Fig.  5.)  It  consists  of  neurofibrils  imbedded  in  a  semifluid  neuroplasm  and 
surrounded  by  a  very  delicate  membrane,  the  axolemma.  The  fibers  are 
described  as  of  two  types,  medulla  ted  and  nonmedullated, 
depending  upon  the  presence  or  absence  of  a  sheath  known 
as  a  medullary  or  myelin  sheath.  The  medullary  sheath 
contains  myelin — a  chemical  substance  made  up  largely 
of  lecithin,  and  supported  by  a  framework  of  neurokeratin. 
Outside  of  the  myelin  is  a  delicate  nucleated  sheath  known 
as  the  sheath  of  Schwann  or  neurolemma.  Thenonmedul- 
ated  or  nonmyelinated  are  also  known  as  the  fibers  of 
Remak.  They  have  a  nucleated  sheath  similar  in  char- 
acter to  the  sheath  of  Schwann.  According  to  Ranson 
(1912),  the  number  of  such  nonmyelinated  fibers  is  much 
larger  than  formerly  was  thought.  The  nonmedullated 
fibers  of  the  peripheral  nerves  arise  from  the  cells  of  the 
sympathetic  and  spinal  ganglia. 

The  medullated  fibers  are  surrounded  by  a  strand  of 
sheath  cells  forming  the  sheath  of  Schwann  or  neurolemma. 
Each  cell  joins  with  the  adjacent  cell,  at  which  point 
there  is  a  slight  constriction  of  the  sheath  forming  a 
node  of  Ranvier.  A  single  sheath  cell  and  its  nucleus, 
which  lies  upon  the  inner  surface  of  the  sheath,  is  found 

between  each  node.     (See  Fig.  6).     The  collaterals  of  the        fic.     6.--Schematic 

rr        ,         ,  . ,  ,  r  T5  •  T^,  drawing  of  myelinated 

neuraxes  are  given  off  only  at  the  nodes  of  Ranvier.     The     nerve  fiber.    A  segment 

neurolemma  extends  from  just  below  the  origin  of  the     between  nodes  of  Ran- 

.  ,,  ,.  ,,  .      ,  ,         .  .        vier.       a.     Sheath     of 

neuraxis  from  the  ganghon  cell  or  spmal  cord  to  its  pen-     g^-hwann;   b,    node  of 

pheral  termination.     Within  the  myelin,  and  extending     Ranvier,  cement  sub- 

.,  ,  .  ,   ,.      .      ^  ,  .        .  stance;    c,    striation  of 

Irom  the  neurolemma,  is  a.  aencdite  Jrameivork  constituting 

the  neurokeratin. 

As  has  been  said,  the  nonmedullated  fibers  differ  from 
the  medullated  by  the  absence  of  the  medullary  sheath. 
This  nerve  fiber  is  enclosed  in  a  very  thin,  fine  membrane. 
Here  and  there  on  the  neuraxis  an  ovoid  nucleus  is 
seen,  surrounded  by  a  small  quantity  of  protoplasm  which  extends  along  the 
axone  enveloping  it.  This  nucleus,  with  its  thin  layer  of  surrounding  proto- 
plasm, may   be  regarded   as   the  sheath  of  the  nonmedullated  fiber. 


Fromann;  d,  axolemma; 
e,  myelin;  /,  Schmidt's 
incisures  (probably 

artifacts);  g.  perinu- 
clear protoplasm;  h, 
nucleus  of  neurolemma; 
/',  neuraxis.  (Cajal, 
Hist,  du  syst.  nerveux.) 


24 


SURGICAL    AND    MKCHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Both  meduUated  and  nonmedullated  fibers  are  assembled  in  nerve  bundles 
called  funiculi,  and  the  funiculi  in  turn  are  joined  together  into  a  larger  group 
by  a  surrounding  sheath  of  connective  tissue  called  epineurium,  thus  forming 
a  peripheral  nerve.  The  individual  fibers  of  the  funiculi  are  separated  by  a 
small  amount  of  connective  tissue  called  endonciirium  and  the  funiculi  are  sur- 
rounded by  a  lamellated  layer  of  fibrous  tissue  which  encircles  the  funiculi, 
called  byKey  and  Retzius  (1873)  perineurium.     (See  Fig.  7.)     Between  the 


Venl 


— .e^"  WSJ/.--"" 


c «» 


Spina.L 


Dorsal 
primary 


Ra.rnus 
CommunLCa.ns 


Fig.  8. — Section  from  a  12  ram.  pig  embryo  showing  the  formation  of  a  spinal  nerve. 

layers  of  the  perineurium  small  spaces  are  found  which  communicate  with  the 
lymph  clefts  between  the  nerve  fibers,  and  in  which  lie  the  majority  of  the  blood 
vessels. 

THE  DEVELOPMENT  OF  THE  PERIPHERAL  NERVE 

Formation  of  Ganglionic  Crest. —  Schulte  and  Tilney  (18 15)  have  shown 
that  the  ganglionic  crest,  which  extends  as  two  lateral  folds  along  the  neural 
tube,  is  formed  by  a  process  of  evagination  from  the  neural  tube  with  subse- 
quent delamination  which  takes  place  cephalocaudad  along  the  dorsal  portion 
of  the  neural  folds.  These  authors  found  an  evagination  and  massing  of  cells 
on  the  ental  surface  of  the  neural  folds  close  to  the  neurosomatic  junction,  but 
in  later  stages  ''delamination  ....  may  be  substituted  for  evagination  and 


Fig.  7. — Drawing  of  a  cross  section  of  a  typical  nerve.  Mallory  connective  tissue  stain.  Con- 
nective tissue  blue.  Blood  vessels  red.  Epineurium — connective  tissue  sheath  surrounding  the 
nerve  as  a  whole.  Perineurium — connective  sheath  between  the  funiculi  and  surrounding  them. 
Endoneurium — the  supporting  connective  tissue  within  the  funiculi. 

Note  the  large  number  of  blood  vessels  throughout  the  section  in  the  epineurium  perineurium 
and  endoneurium. 


ANATOMY    OF    THE    SPINAL    NERVE 


2  5 


a  solid  anlage  may  replace  a  hollow  one "     Most  of  the  cells  which 

form  the  ganglionic  crest  separate  from  the  neural  tube  and  extend  latero- 
ventrad  between  the  neural  tube  and  the  ectoderm  until  they  may  lose 
temporarily  their  connection  though  some  of  the  cells  remain  permanently 
within  the  tube.  From  the  ganglionic  crest  the  capsule  and  afferent  ganglionic 
cells  and  their  processes  arise,  as  well  as  the  sheath  cells  and  the  sympathetic 
ganglia. 


Arcus  vertebralis 
Mm.  dorsalea 


Radix  posterior 

;      Kamus  posterior 


R.  medialis 

c^'R.  lateralis 


M.  intercost.  ext. 


M.  intercost. 
int. 


Fig.  9. — Diagrammatic  transverse  section  througii  a  thoracic  segment  of  a  17  mm.  human 
embryo  (Huber  collection,  No.  14),  showing  a  typical  thoracic  nerve.  Enlarged  15:1.  (From 
Keibel  and  Mall,  "Human  Embryology") 

Changes  in  Ganglionic  Crest. — The  cells  of  the  ganglionic  crest  pro- 
liferate and  undergo  further  differentiation  forming  slender  central  processes 
which  re-unite  secondarily  with  the  spinal  cord.  These  processes  constitute 
the  axones  of  the  ganglion  cells  and  make  up  the  dorsal  root  of  the  spinal 
nerve.  Slender  processes  also  appear  later  at  the  opposite  poles  of  the  cells,  the 
cells  at  this  stage  being  bipolar.  By  gradual  shifting  of  the  cell  body,  the  two 
processes  are  united,  forming  the  unipolar  cells  of  the  higher  vertebrates,  while 
in  the  lower  forms  (amphioxus,  cyclostomes)  and  in  the  acoustic  ganglia  of 
all,  bipolar  cells  are  found.  In  the  spinal  region  of  the  embryo  the  crest 
becomes  segmented  along  its  ventral  margin  forming  neuromeres,  which  corre- 


26  SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 

spond  in  number  to  the  muscle  segments  (myotomes),  and  eventually  each  of 
these  segmented  masses  of  ganglion  cells  becomes  a  ganglion  of  the  dorsal  root 
of  the  spinal  nerves.  The  ganglionic  crest  contains  also  supporting  cells,  from 
which  the  capsule  and  sheath  (neurolemma)  cells  arise,  as  well  as  ganglion  cells 
which  give  origin  to  the  afferent  (sensory)  nerve  fibers,  the  central  processes 
making  up  the  dorsal  roots  and  the  peripheral,  the  afferent  fibers  of  the  peri- 
pheral nerves.     (See  Figs.  8-9.) 

Formation  of  the  Ventral  Root. — While  the  ganglionic  crest  is  undergoing 
proliferation  and  segmentation,  the  cells  within  the  neural  tube  are  proliferating, 
and  further  differentiation  occurs.  Two  types  of  cells  are  distinguishable,  the 
spongioblasts  and  the  neuroblasts,  the  former  having  branches  and  processes 
connecting  with  each  other,  the  latter  moie  or  less  pear-shaped  and  arranged 
in  clusters,  having  a  small  central  protoplasmic  process  growing  out  from  one 
pole — the  axone.  The  axones  tend  to  group  themselves  into  protoplasmic 
strands  and  may  extend  either  into  other  parts  of  the  neural  tube,  forming 
association  paths  within  the  central  nervous  system,  or  the  strands  may  pene- 
trate the  neural  wall  and  grow  out  into  the  mesoderm,  thus  forming  the 
primitive  ventral  motor  root.  (See  Figs.  8-9.)  Later  when  the  motor  root  has 
further  advanced,  a  few  cells  begin  to  migrate  from  the  neural  canal  along  the 
neuraxes.  These  are  sheath  cells.  All  the  sheath  cells  thus  have  their  origin 
from  the  neural  tube  or  ganglionic  crest;  a  point  which  proves  their  close  relation 
to  the  neuroglia.  Allen  has  shown  in  the  shark  embryo  that  the  motor  or 
effector  fibers  of  the  spinal  nerve  develop  considerably  in  advance  of  the  sensory; 
but  the  cells  destined  to  become  neurolemma  migrate  from  the  ventral  lateral 
surface  of  the  spinal  cord  at  a  later  date  than  those  from  the  dorsal  root. 

Origin  of  Sheath  Cells. — The  capsule  and  sheath  cells  arise  principally 
from  the  ganglionic  crest,  and  only  after  the  nerve  is  more  advanced  in  its 
development  do  they  extend  along  the  ventral  root  from  the  neural  tube. 
The  sheath  cells  in  their  migration  along  the  nerve  fibers  at  first  enclose  only 
large  bundles,  but  later,  by  multiplication,  these  cells  penetrate  between  the 
neuraxes  until  each  neuraxis  is  enclosed. 

Two  types  of  sheath  cells  are  formed:  one  constitutes  the  sheath  of 
Schwann  and  enclosing  fibers  which  become  myelinated,  and  the  other  surrounds 
the  fibers  without  myelinization.  The  sheath  cells  appear  before  myelinization 
takes  place.  The  source  of  the  myelin  is  not  exactly  known,  but  it  is  thought  to 
be  formed  by  the  sheath  cells.  The  time  of  myelinization  varies,  occurring  first 
in  those  fibers  phylogenetically  oldest  and  in  those  which  functionate  earliest. 


ANATOMY    OF    THE    SPINAL    NERVE 


27 


Experimental  Evidence  to  Show  Origin  of  Neuraxes  and  Sheath  Cells. — 

Two  main  theories  have  been  offered  concerning  the  origin  of  the  neuraxes,  one 
the  oulgroiiih  theory  of  His  (1890)  and  the  other  the  cell  chain  theory  of  Bethe 


Fig,  10. — Semi  diagrammatic  view  of  the  nerves  of  the  abdominal  walls  of  the  frog  larva  (nor- 
mal specimen).  Abd.M.,  abdominal  muscle;  HL.,  rudiment  of  hind  leg;  Mot.N.,  motor  branch  of 
segmental  nerve  running  in  inscriptio  tendinea  of  the  primary  abdominal  muscle;  Mot.Nuc,  motor 
nucleus  (ventral  horn  cells)  in  spinal  cord;  Seg.N.,  segmental  (spinal)  nerve;  Sen.N.,  sensory  branch 
of  spinal  nerve  running  to  integument  outside  of  muscle;  Sp.C,  spinal  cord;  Sp.G.,  spinal  gangUon. 
(Harrison,  Amer.  Jour,  of  Anat.) 

(1903)  and  others.  A  still  older  theory  is  that  of  Hensen,  according  to  wliich 
there  always  are  protoplasmic  intercellular  bridges  in  the  developing  embryo 
and  out  of  certain  of  these  bridges  the  nerve  tiber  is  differentiated.  Held 
(1909)  has  supported  a  modification  of  this  theory;  according  to  him  the  nerve 
fibers  differentiate  from  the  nerve  cell  bodies  along  these  protoplasmic  bridges. 
Likewise  two  main  views  have  been  held  concerning  the  origin  of  the  sheath 
cell,  it  being  formerly  thought  that  the  sheath  cell  was  of  mesodermal  origin 


28 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


and  from  the  surrounding  mesodermal  tissues  invaded  the  nerve  fibers  and 
surrounded  them.  The  more  recent  view  on  the  other  hand  has  been  that  the 
sheath  cells  were  closely  related  to  the  neuroglia  and  were  of  ectodermal  origin. 
Both  of  these  important  questions,  heretofore  unsettled,  have  been  con- 
clusively answered  by  the  experimental  work  of  Harrison  (1907).     By  excising 


Fig.  II. — Semidiagrammatic  view  of  the  nerves  of  the  abdominal  walls  of  a  frog  larva  from 
which  the  ganglion  crest  had  been  removed.  Only  motor  nerves  are  present  and^hese  consist  of 
axis  cylinders  without  sheath  cells.     (Harrison,  Amer.  Jour,  of  .\nat.) 

the  ganglionic  crest  of  frog  larva  this  investigator  has  shown  that  afferent  nerve 
fibers  do  not  develop  and  that  only  efl'erent  fibers  from  the  undisturbed  ventral 
horn  cells  are  found.  Furthermore  the  neuraxes  of  the  ventral  horn  cells  were 
devoid  of  sheath  cells  and  appeared  as  naked  fibers  (See  Fig.  lo-ii).  Harrison 
thus  showed  that  the  ganglionic  crest  is  the  source  not  only  of  the  afferent 
fiber  but  also  the  sheath  cells.  Thus  the  sheath  cell  may  be  considered  as  the 
neuroglia  of  the  peripheral  nerve  and  having  with  the  neuroglia  a  common  ecto- 
dermal origin,  since,  as  has  been  said,  the  ganglionic  crest  is  derived  from  the 
ectoderm.     Harrison  has  further  shown  that  the  growth  of  the  axone  of  isolated 


ANATOMY    or    THE    SPINAL   NERVE  29 

nerve  cells  may  be  observed  in  an  artificial  medium  such  as  coagulated  blood, 
thus  offering  direct  proof  of  the  outgrowth  theory  of  the  nerve  fiber. 

Thus  the  important  deductions  of  these  ingenious  experiments  apply  not  only 
to  the  development  of  nerve  fibers,  but  are  of  equal  value  in  throwing  light  upon 
nerve  regeneration,  the  great  importance  of  the  nerve  cell,  the  relative  unim- 
portance of  the  sheath  cell  for  regeneration,  and  the  secondary  role  these  cells 
play  in  the  formation  of  the  nerve. 

Migration  of  the  Sympathetic  Cells. — During  proliferation  of  the  gang- 
lionic crest  and  its  gradual  shifting  lateroventrad  a  strand  of  both  ganglion 
and  sheath  cells  gradually  migrates  from  the  ventral  border  of  the  crest  to  the 
region  of  the  aorta.  (See  Fig.  8.)  Some  of  these  cells  remain  here  and  form 
cell  clusters — the  primitive  prevertebral  sympathetic  ganglia — while  others 
continue  to  migrate  and  form  the  more  peripheral  sympathetic  ganglia. 
This  strand  from  the  ganglionic  crest  is  the  primitive  ramus  communicans. 
Later,  the  cells  of  the  dorsal  ganglia  and  the  nerve  cells  within  the  basal  part 
of  the  neural  tube  send  fibers  to  the  sympathetic  ganglia;  those  from  the  neural 
tube  (efferent  and  preganglionic)  terminate  within  the  sympathetic  ganglia, 
while  those  from  the  dorsal  ganglia  (afferent)  continue  uninterrupted  through 
the  ganglia  to  their  ultimate  termination  in  the  sensory  end  organs.  These 
fibers,  which  become  medullated,  form  the  white  rami  communicantes.  From 
the  sympathetic  ganglia  small  postganglionic  fibers  pass  to  the  spinal  nerve  as 
axones  of  sympathetic  cells.  The  fibers  of  these  cells  are  nonmedullated,  grey- 
ish in  color,  and  hence  are  called  the  grey  rami  communicantes. 

FUNICULAR  ANATOMY 

Theoretical  Importance  of  Fimicular  Anatomy. — A  finer  anatomy  of  the 
peripheral  nerves  suggests  possibilities  of  exact  methods  of  nerve  repair,  which 
should  lead  to  marked  improvement  in  the  end  results  of  peripheral  nerve 
surgery.  As  more  exact  histological  studies  of  nerve  regeneration  have  led  to 
more  precise  technic  in  the  mechanics  of  nerve  suture,  so  more  exact  knowl- 
edge of  the  finer  morphological  structure  of  the  nerve  trunk  should  also  lead 
to  greater  nicety  in  the  union  of  nerve  ends  and  eventually,  perhaps,  to  funic- 
ular suture  as  well  as  truncular.  If  there  exists  within  the  nerve  trunk 
definite  funiculi  or  nerve  paths  destined  to  serve  certain  muscles,  or  sensory 
areas,  which  are  constant  in  their  position  at  different  levels,  the  more  accurate 
the  approximation  of  these  paths,  the  better  the  results,  and  the  less  the  loss 
or  dispersion  of  fibers  into  paths  foreign  to  them,  for  example,  sensory  into  motor 
and  vice  versa,  etc. 


30  SURGICAL   AND   MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 

Evidence  not  in  Support  of  Stoffel's  View. — However,  there  is  some  con- 
troversy concerning  the  existence  of  separate  and  delinite  paths  over  any  great 
length  within  the  nerve  trunk.  Stoffel  and  his  followers  claim  that  a  definite 
internal  topography  with  a  definite  nerve  pattern  exists  throughout  the  nerve 
trunk,  with  definite  paths  destined  to  definite  muscles  and  muscle  groups. 
Such  a  conception  has  been  vigorously  denied  by  Heinmann  (1916),  Borchardt 
and  Wjasmenski  (1917)  ,  Langley  and  Hashimoto  (191 7),  Compton  (191 7), 
Dustin  (1918),  Kunzel  (1918)  and  others.  Heinmann  holds  that  the  method  of 
funicular  nerve  suture  insisted  upon  by  Stoffel  has  materially  discouraged 
nerve  suture  and  also  that  the  theoretical  basis  of  Stoffel's  views  on  internal 
topography  are  erroneous. 

Heinmann  studied  the  internal  structure  of  the  musculospiral,  ulnar, 
median  and  sciatic  nerves  in  macerated  dissections  and  found  many  internal 
nerve  plexuses,  which  he  beHeved  disproved  Stoffel's  theory  of  the  existence  of 
definite  nerve  paths  from  the  large  nerve  plexuses  to  the  periphery.  Such 
definite  nerve  paths  Heinmann  found  only  in  a  few  places  and  over  a 
very  short  course;  for  example,  the  nerve  path  for  the  gastrocnemii  ran 
as  a  separate  bundle  only  for  a  short  distance  and  then  joined  one  of  the  plexuses 
in  the  nerve  and  no  longer  existed  as  a  definite  and  distinct  bundle.  Hence, 
only  in  such  restricted  portions  of  the  nerve  trunks  could  Stoffel's  operative 
method  be  used.  In  addition  to  these  dissections,  Heinmann  imbedded  two 
nerves  side  by  side  and  made  a  series  of  cross  sections,  staining  them  by  the 
Weigert  method.  The  appearance  of  the  cross  sections  varied  greatly  and  no 
constant  appearance  in  either  nerve  was  found  when  sections  were  made  at 
corresponding  levels  even  with  such  complete  exposure  as  could  not  be  dupli- 
cated in  any  operative  wound.  He  believes  that  the  task  of  learning  the 
anatomical  appearance  of  such  cross  sections,  with  the  exception  of  a  few 
areas  which  are  constant  in  certain  nerves,  would  be  as  futile  as  it  would  be 
difficult. 

In  speaking  of  these  internal  plexuses,  Compton  (191 7)  states  that  "'proxi- 
mal to  the  plexus,  these  bundles,  although  superficially  continuous  with  the 
nerves  below,  have  partly  lost  their  identity,  through  interchange  of  fibers," 
and  that,  "one  of  the  functions  of  the  plexuses  in  the  nerve  trunks  is  to  supply 
each  muscle  several  routes  by  which  impulses  may  reach  it."  Thus,  in  case 
one  path  is  blocked,  several  others  are  still  available.  Dustin  (1918)  has  also 
shown  that  morphologically  the  funicular  arrangement  varies  at  each  level 
and  cross  sections  do  not  appear  similar  within  the  corresponding  nerve  in 


ANATOMY    OF    THE    SPINAL   NERVE 


31 


Ulnao-  border 


Rijdial  boricr 


Communication  telween 
tneciiau  6  ulnar  H. 


CommunicaKon  of 
incdlianN    to 
deepbr  of 
UlitirN, 
(Intrinsic  muscles) 
^     of  hand       / 


.•4a^ 


Wrist 


Fig.  12. — Macerated  dissection  of  the  left  ulnar  and^median  nerves  showing  two  types  of  com- 
munication between  these  nerves.  The  bundles  of  the  ulnar  nerve  have  been  dissected  free  and 
separated.  D,  short  communication;  E,  long  communication  to  the  deep  branch  of  the  ulnar  (in- 
trinsic muscles  of  the  hand).  10,  Branch  to  pronator  teres,  humeral  head,  upper  part,  and  lower 
part  of  muscle;  2a,  branch  to  superior  belly,  flexor  indicis  sublimis;  2b,  branch  to  palmarislongus; 
3,  branch  to  flexor  digitorum  subUmis,  3d,  4th  and  5th  fingers;  4a,  branch  to  flexor  digitorum 
profundus,  3d,  4th  and  sth  fingers;  46,  branch  to  flexor  poUicis  longus;  4c,  anterior  interossous 
nerve;  5,  branch  to  deep  belly  of  flexor  indicis  sublimis;  6a  and  6b,  branch  to  flexor  carpi  ulnaris; 
7.  dorsal  cutaneous  branch  of  the  ulnar  nerve,  8,  palmar  cutaneous  branch  of  the  ulnar  nerve;  9, 
deep  muscular  branch  of  the  ulnar  nerve;  10,  superficial  branch;  11,  palmar  cutaneous  branch  of 
the  median  nerve.     (After  Borchardt  and  Wjasmenski.) 


32  SURGICAL   AND    MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 

Median   N.  rijW 


Outer  head 


Inner  head 


Radial  Ixjixler 


Ulnar  border 
■?at3 
■  la.*  lb 


Musculo - 

CutiTWOUsN.  ■^.. 

(muicular  brs ) 


Cutaneous 
brandies 


Klblc 


lalfelc 


Ulblc 


lalblc 


1& 


1^  ■- 

Va-.JJ/    "■"-•!c 

Fig.  13. — Median  and  musculocutaneous  nerves,  macerated  dissection.  Bundle  i,  la,  \h,  ic 
lies  on  the  ulnar  border  below  and  crosses  to  the  radial  above.  The  bundle  to  the  pronator  teres 
la  and  li  passes  through  the  inner  head  of  the  median  and  the  bundle  to  the  flexor  carpi  radialis 
IC  through  the  outer  head.  On  the  ulnar  side  of  the  bundle  i,  \a,  ib,  ic,  lies  the  bundle  for  the 
fle.xor  indicis  sublimis  (sup.  head).  This  bundle  and  the  bundle  to  the  flexor  digitorum  sublimis 
3d,  4th,  5th  fingers;  3,  pass  through  the  inner  head.  The  cross  section  appearance  of  various 
levels  at  2  cm.  intervals  are  shown.  Note  the  marked  difference  of  the  cross  section  appearance  at 
each  level.     (Modified  after  Borchardt  and  Wjasmenski.) 


ANATOMY    OF    THE    SPINAL    NERVE 


33 


Median  N.  left 


3  cmhi( 


3  c  TuKigKcp 


2  c  Til  higher 

thATlC. 


the  same  indi\idual  even  though  the  sections  are  made  at  3  cm.  intervals. 
Considerable  variance  is  found  in  the  corresponding  nerves  in  the  same 
individual  and  in  different  individuals.  Dustin  believes  that  "it  is  possible 
to  cstiililish  as  a  principle,  that  tlic  identical  arrangement  is  never  found  at 
the  same  levelin  two  different  individuals  .  .  .  and 
that  it  is  impossible  to  conceive  of  a  functional  sys- 
tcmatization  of  a  nerve  having  funiculi  as  its  anatomi- 
cal basis." 

Dissection  of  Macerated  Nerve  Trunks. — In 
studying  peripheral  nerves  by  means  of  macerated 
dissections  so  as  to  bring  out  finer  funicular  connec- 
tions Borchardt  and  Wjasmenski  found  in  more  than 
fifty  cadavers  that  throughout  the  entire  nerve 
course  there  were  numerous  internal  plexuses,  with 
frequent  interchange  of  fibers  from  the  different 
funiculi.  In  the  median  nerve,  one  or  two  paths 
were  found  to  have  a  definite  course  from  the  for- 
mation of  the  median  nerve  to  their  ultimate  dis- 
tribution. However,  even  these  received  numerous 
communications  and  their  position  within  the  nerve 
trunk  varied.  Figures  12  and  13  illustrate  the 
great  complexity  and  intermingling  of  the  nerve 
fibers  which  takes  place  before  the  path  finally 
makes  its  exit  from  the  nerve  trunk.  As  a  result 
of  this  elaborate  study,  these  authors'  conclusions 
differ  greatly  from  those  of  Stoffel's  school — "ac- 
cording to  our  findings,  the  motor  paths  lie  more 
or  less  constant  only  a  short  distance  from  the  point 
at  which  they  leave  the  nerve  stem."  The  con- 
clusion is  reached  that  "it  is  impossible  to  rely 
alone  upon  the  anatomical  relations  .  .  .  without 
electrical  stimulation  (of  the  separate  funiculi). 
Exact  knowledge  of  the  individual  paths  is  difficult 
or  almost  impossible."  Morphologically,  the  nerve 
trunk  varies  greatly  with  each  cross  section,  so  that  if  2 , 

nerve  ends,  which  frequently  is  the  case  clinically,  identification  of  the  corre- 
.3 


Ulua.r 
border 
Fig.    14.- 


?1  cm  &bovG 
/  internal  condyle 

Ra-ciiad. 
border 

-Cross  section  of 
human  median  nerve  (left). 
The  marked  differences  in  the 
cross  section  appearance  of  the 
median  nerve  at  various  levels 
are  seen.  To  unite  identical 
bundles  in  the  presence  of  large 
nerve  defects  is  impossible. 
(Borchardt  and    Wjasmenski.) 


,  4  or  6  cm.  separate  the  two 


34  SURGICAL   AND   MECHANICAL    TREATMENT    OF    PERIPHERAL   NERVES 

spending  nerve  paths  within  the  distal  and  central  stumps  becomes  impossible. 
(See  Fig.  14.) 

Funicular  Identification  by  Bipolar  Stimulation. — By  means  of  bipolar 
stimulation  on  the  surface  of  various  nerves  exposed  at  operation,  Marie,  Gosset 
and  Meige  (1915)  have  somewhat  strengthened  the  view  of  Stoffel  (1913)  that 
there  exist  definite  nerve  paths  from  the  large  plexuses  to  the  periphery.  By 
comparing  the  results  of  such  stimulation  on  different  nerves,  and  certain 
definite  surface  points,  presumably  constant,  in  different  nerves,  they  have  been 
able  to  map  out  to  some  extent  a  surface  topography  which  seems  to  indicate  a 
definite  funicular  arrangement  within  the  nerve  trunk.  By  this  means,  Putti 
(1916),  Kraus  and  Ingham  (1920)  have  come  to  similar  conclusions. 

Surface  topography  of  the  funicular  arrangement  in  peripheral  nerves  as 
studied  by  means  of  the  bipolar  electrode  oft'ers  numerous  obstacles  to  accurate 
funicular  determination.  Not  only  is  variance  found  in  a  given  nerve  at 
similar  levels  in  the  same  individual,  but  also  in  corresponding  nerves  in  other 
individuals.  A  further  obstacle  exists  in  the  fact  that  it  is  rarely  possible  for 
the  examiner  to  say  with  assurance  that  any  given  point  in  one  nerve  cor- 
responds with  a  similar  point  in  another  nerve,  especially  when  the  operations 
are  done  at  difTerent  times  with  the  extremities  in  positions,  although  similar, 
yet  probably  not  identical.  Marie,  Gosset  and  Meige,  in  describing  the  technic 
used  in  their  localization  tests,  speak  of  the  nerve  to  be  examined  as  "free  over 
an  area  of  6  to  8  cm."  and  that  "  two  glass  rods  were  passed  beneath  the  nerve."' 
By  such  displacement  of  the  nerve  some  variation  in  the  position  of  the  nerve 
trunk  may  occur,  though  every  precaution  be  taken  to  avoid  such  displacement. 
The  variability  in  length  of  the  extremities,  the  variability  in  the  position  of  the 
extremity  in  different  operations,  as  well  as  the  variability  in  relative  position 
at  which  branches  arise  from  a  given  nerve,  make  precise  comparison  of  corre- 
sponding points  on  a  nerve  too  doubtful  to  be  scientifically  accurate.  Another 
point  is  the  fact  that  in  most  nerves  of  the  extremities  a  variable  degree  of  tor- 
sion in  their  longitudinal  axis  normally  takes  place  which  makes  precision  in 
comparative  surface  localization  difficult.  Still  another  variant  to  be  con- 
sidered is  that  of  the  relation  of  the  funiculi  to  the  surface  in  different  nerves 
which  makes  it  impossible  for  the  examiner  to  know  just  which  funiculus  lies 
under  a  given  quadrant  of  the  surface  and  to  which  funiculus  the  response  may 
be  attributed.  Topographical  stimulation  is  accurate  only  for  the  identical  nerve 
examined  at  the  time  examined  and  at  the  point  examined. 

Unfortunately  surgical  repair  of  severed  nerves  is  demanded  usually  after 


ANATOMY    OF    THE    SPINAL    NERVE  35 

complete  severance  and  generally  at  a  time  when,  due  to  degeneration,  the 
distal  segment  no  longer  responds  to  electrical  stimulation.  Consequently, 
electrical  stimulation  of  the  individual  funiculi  in  the  cross  area,  the  only 
precise  means  of  accurately  determining  funicular  arrangement,  is  not  clinically 
possible.  Topographical  locahzation  by  means  of  the  electrode  can  be  accurate 
only  when  the  separate  funiculi  are  stimulated  in  freshly  made  cross  sections) 
and  each  stimulation  checked  by  serial  section  of  the  nerve  in  question. 

Internal  Nerve  Plexuses. — The  existence  of  intercommunicating  funiculi 
within  the  nerve  trunk  has  long  been  recognized.  However,  it  is  only  lately 
that  the  significance  of  such  plexuses  in  relation  to  nerve  surgery  has  been 
appreciated.  In  the  rabbit,  cat,  dog  and  human  Langley  and  Hashimoto 
(igiy)  found  that  the  sciatic  nerve  was  made  up  of  bundles  or  bundle  groups, 
which,  with  few  exceptions,  rarely  ran  a  separate  and  distinct  course  over  any 
great  distance  and  which  usually  formed  internal  nerve  plexuses,  particularly 
in  regions  near  which  branches  arise.     (See  Fig.  15.) 

Between  these  internal  nerve  plexuses  regions  are  found  in  which  the 
funiculi  are  more  or  less  distinct,  though  they  still  show  some  intermingling  and 
communications,  yet  not  so  marked  as  in  the  plexuses.  These  areas  are  called 
intermediate  regions  (Langley  and  Hashimoto)  or  zone  nodale  (Dustin). 
Such  a  region  is  especially  likely  to  exist  where  there  is  considerable  distance 
between  the  origins  of  branches  from  the  nerve.  The  greater  the  distance 
between  branches,  generally  speaking,  the  greater  the  length  of  the  inter- 
mediate region.  Langley  and  Hashimoto  say  that,  "in  the  peroneal  portion 
of  the  sciatic  nerve  there  is  no  part  longer  than  i  or  2  cm.  in  which  there  are 
no  plexuses."  Similar  plexus  arrangement  is  found  in  the  nerves  of  the  upper 
extremity.  Dustin  found  that  plexuses  were  especially  seen  near  levels  at 
which  nerve  branches  were  about  to  be  given  off,  and  that,  conversely,  the 
intermediate  regions  were  found  in  those  parts  of  the  nerve  trunk  where 
branches  were  not  given  off.  In  the  corresponding  nerves  of  difi'erent  individ- 
uals, the  intermediate  zones  may  be  markedly  diminished  or  nearly  absent, 
and  the  entire  nerve  trunk  be  made  up  of  numerous  small  funiculi  or  areas  in 
which  the  funiculi  are  collected  into  one  or  two  or  three  larger  funiculi.  Thus 
there  is  considerable  variance  in  the  longitudinal  extent  and  in  the  amount  of 
intermingling  of  the  fibers.  These  communications  serve  to  collect  together 
the  aft'erent  and  efferent  fibers  of  different  nerve  roots  for  the  area  suppUed  by 
the  peripheral  nerves"  (Langley  and  Hashimoto).  Hence,  the  rearrangements 
generally  take  place  both  immediately  above  the  level  at  which  branches  are 


36 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


U4     cm. 


Fig.  15. — Origin  of  nerves  from  the  sciatic  plexuses  in  man.  The  plexus  is  only  drawn  at  the 
point  of  origin  of  the  nerves  and  irrespective  of  whether  it  is  in  the  anterior  or  posterior  surface. 
The  brackets  show  the  extent  of  t'.P.,  upper  plexus;/,  intermediate  region;  Z,. P.,  lower  plexus,  in  the 


ANATOMY    OF    THE    SPINAL    NERVE  37 

to  be  given  off,  and  again  immediately  below  in  preparation  for  the  rearrange- 
ment of  the  branches  to  be  given  off  still  lower.  Compton  and  also  Langley 
and  Hashimoto  conclude  that  "the  complexity  of  the  lower  plexuses  in  the 
sciatic  of  the  larger  mammals  makes  it  certain  that  so  far  as  dissection  goes,  no 
bundle  above  the  plexuses  can  be  said  to  correspond  even  approximately  with 
any  bundle  below  it."  Speaking  for  the  nerves  of  the  upper  extremity,  Dustin 
found  that  "  the  funicular  topography  of  the  same  nerve  is  continuously  modi- 
fied by  the  exchange  between  different  funiculi  through  numerous  anastomoses." 
Compton,  Langley  and  Hashimoto,  and  Dustin  further  conclude  that  separate 
suture  of  the  individual  bundles,  so  as  to  attain  accurate  apposition,  seems 
hardly  feasible,  for  even  the  slightest  rotation  would  suffice  to  distort  the  nerve 
pattern.  Furthermore,  such  separate  suture  is  hardly  to  be  expected  either 
above  or  within  a  nerve  plexus,  whereas  suture  of  the  funiculi  below  the  level 
of  the  plexuses  from  which  the  funiculi  have  arisen  would  serve  to  prevent 
distortion  of  the  pattern  and  poor  shunting  of  the  neuraxes. 

In  the  branches  immediately  below  the  plexuses,  the  funicular  arrangement 
is  fixed,  and  any  distortion  resulting  from  suture  cannot  readjust  itself  within 
the  nerve  trunk,  hence  can  be  overcome  only  by  re-education  through  central 
readjustment.  Hence,  in  the  areas  where  the  funiculi  are  fixed,  particular 
attention  must  be  paid  to  funicular  union.  The  objections  suggested  by 
Langley  and  Hashimoto  to  the  prolonged  time,  essential  to  such  suture,  needs 
hardly  to  be  considered,  and  the  amount  of  scar  tissue  resulting  which  these 
authors  think  also  objectionable  can  be  minimized  by  scrupulous  care  in  the 
technic  and  the  avoidance  of  trauma  such  as  is  gained  by  using  a  constant 
stream  of  salt  solution,  in  place  of  sponging  the  nerve  ends,  etc. 

In  most  instances,  when  a  multiple  graft  is  done  experimentally,  it  has  not 
been  possible  to  observe  the  normal  funicular  arrangement.  Yet,  in  spite  of 
this  disregard  of  the  internal  arrangement  of  the  nerve  paths,  these  animals 

respective  peroneal  and  tibial  divisions.  In  the  peroneal,  P,  marks  a  stretch  of  the  upper  plexus  in 
which  the  plexus  was  less  than  above  and  below  it;  /,  marks  a  stretch  in  which  the  characters  of  the 
intermediate  region  were  less  developed  and  the  plexus  greater  than  below.  In  the  tibial,  P  marks 
a  portion  of  the  intermediate  region,  in  which  rather  more  than  a  third  of  the  nerve  had  scarcely  any 
plexus,  the  rest  had  a  moderately  developed  plexus.  The  upper  half  of  the  lower  ple.xus  of  the  tibial 
consisted  of  a  varying  number  of  bundle  groups  running  at  different  points  an  isolated  course  for 
2-3  centimeters.  In  the  external  popliteal  the  beginning  of  the  plexus  formed  by  the  three  bundle 
groups  is  shown.  The  nerves,  the  bundles  61,  bi  and  some  bundles  connected  with  61  are  pulled 
away  from  the  trunk;  H,  hamstring  nerves;  B,  nerve  for  femoral  head  of  biceps;  T.S.,  tibial  saphe- 
nous; F. 5.,  peroneal  saphena;/'.C.,  lateral  cutaneous; G,  nerve  to  gastrocnemius;  ,4,  probably  articular 
branch,  bia,  Bundle  arising  from  the  upper  plexus  and  running  a  long  separate  course,  most  of  the 
fibers  of  .1,  came  from  it.  ija,  Long  separate  bundle  arising  from  the  intermediate  region.  (J.  N. 
Langley  and  M.  Hashimoto,  Journal  of  Physiology,  1917.) 


38  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

show  return  of  function,  with  formation  of  motor  end  plates  within  the  muscles 
and  contraction  of  the  muscles  on  stimulation  of  the  nerve  trunk,  both  above 
and  below  the  graft. 

By  the  passage  of  neuraxes  through  multiple  grafts,  it  would  seem  that 
whatever  funicular  arrangement  had  previously  existed  was  thereby  greatly 
dispersed,  and  yet  functionally  excellent  motor  re-establishment  takes  place. 
Kennedy  (1901)  has  reported  that  after  nerve  crossing,  in  which  a  flexor  nerve 
was  sutured  to  an  extensor,  re-establishment  of  function  occurred  almost  as 
early  as  when  the  same  nerve  was  cut  and  resutured. 

Prevention  of  Even  Minimal  Axial  Rotation  Difficult. — From  a  practical 
standpoint,  in  end  to  end  suture  without  loss  of  substance,  even  under  favorable 
conditions,  slight  axial  rotation  of  the  nerve  ends  of  only  a  few  millimeters  is  not 
only  most  probable,  but  almost  certain  to  occur.  Such  slight  rotation  might 
suffice  in  many  instances  to  prevent  apposition  of  corresponding  funiculi.  Dis- 
tortion is  perhaps  still  more  apt  to  occur,  even  with  the  least  rotation,  in  those 
nerves  in  which  the  funiculi  are  small  and  numerous,  such  as  the  median  in 
certain  locations,  and  the  ulnar  nerve.  This  fact  may  account,  in  part  at  least, 
for  the  relatively  poor  functional  return  in  the  latter  nerve.  Funicular  apposi- 
tion is  also  unUkely  at  certain  levels  in  all  nerves  in  which  the  funicular  arrange- 
ment is  fixed.  These  technical  difficulties,  together  with  the  variations  of  size 
and  arrangement  in  cross  sections  of  the  same  nerve  at  different  levels,  make 
accurate  funicular  apposition  most  difficult,  particularly  when  loss  of  substance 
has  occurred.  In  nerve  surgery,  the  best  which  can  be  done  is  to  try  to  prevent 
axial  rotation  of  the  nerve  trunk  by  stay  sutures.  When  this  is  impossible  due 
to  loss  of  anatomical  continuity,  one  can  only  approximate  the  nerve  ends, 
paying  careful  attention  both  to  the  position  of  the  nerve  trunk  within  its 
bed  above  and  below  the  Hne  of  suture  as  well  as  to  the  appearance  of  the  cross 
sections.  At  best,  under  such  circumstances,  exact  funicular  apposition  is 
unlikely. 

In  some  nerves  at  certain  levels  a  distinct  funicular  arrangement  can  be 
recognized,  even  though  there  is  loss  of  substance.  This  is  particularly  true  for 
instance  of  the  musculospiral  nerve  in  the  lower  third,  the  peroneal  near  the 
head  of  the  fibula,  the  median  near  the  bend  of  the  elbow  and  the  ulnar  at  the 
bend  of  the  elbow.  These  positions  correspond  in  each  nerve  to  levels  at  whicli 
branches  are  about  to  be  given  off,  and  consequently  the  funiculi  to  form  each 
branch  are  more  or  less  isolated  at  a  point  a  short  distance  above  its  exit. 


ANATOMY    OF    THE    SPINAL    NERVE  39 

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on  the  development  of  spinal  ^nerves,  J.  Comp.  _Neur.,  v.  128:  No.  i,  August,  1917 

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Bethe,  a.:  AUgemeine  Anatomie  und  Physiologic  des  Nervensystems,  Leipzig,  G.  Thieme, 

1903. 
BoHM,    A.    A.,    Davidoff,    M.    and    Hltber,    G.    Carl:  Text-book  of  Histology,  W.  B. 

Saunders  Company,  Phila.  &  London,  1904. 
BoRCHARDT,   M.   and  Wjasmenski:  Der   Nervus  Medianus,  Beitr.  z.  klin  Chir.,  v.  107: 

1917,  P-  553- 
COMPTON,  A.  T. :  The  intrinsic  anatomy  of  the  large  nerve  trunks  of  limbs,  J.  Anat.  &  Physiol., 

v.  51:   1916-17,  p.  103. 
DuSTiN,  A.  P.:  La  Fasciculation  des  nerfs,  son  importance  dans  le  diagnostic,  le  pronostic 

et  le  traitement  des  lesions  nerveuses.  Ambulance  de  "L'Ocean"  tome  2:  July,  1918,  p. 

135- 
Harrison,  R.  G.:  E.xperiments  in  transplanting  limbs  and  their  bearing  upon  the  problems 

of  the  development  of  the  nerves,  J.  Exper.  Zool.,  v.  4:   1907,  p.  23Q. 
Further  experiments  on  the  development  of  peripheral  nerves,  Am.  J.  Anat.,  v.  5:   1906, 

p.  121. 
On   the   Differentiation   of   muscular   tissue  when  removed  from  the  influence  of  the 

nervous  system,  ."Vm.  J.  Anat.,  v.  2:  1903  (Proceedings),  p.  iv. 
Heinemann,  O.:  Ueber  Schussverletzungen  der  peripheren  Nerven,  nebst  anatomischen 

Untersuchungen  fiber  den  inneren  Bau  der  grossen  Nervenstamme,  Arch.  f.  klin.  Chir., 

V.  108:  August,  1916,  p.  107. 
Held,  Hans.:  Die  Entwicklung  des  Nervengewebes  bei  den  Wirbeltieren,  Leipzig,  Verlag 

von  Johann  Ambrosius  Barth,  1909. 
Hensen,  v.:  Die  Entwicklungsmechanik  der  Nervenbahnen  im  Embryo  der  Saugetiere, 

Kiel  und  Leipzig,  1903. 
His,  W.:  Histogenese  und  Zusammenhang  der  Nervenelemente,  Arch.  f.  Anat.  u.  Entwicke- 

lungsgeschichte,  Suppl-Bd.,  1890,  pp.  95-117. 
JoHxVSTON,  J.  B.:  The  Nervous  System  of  Vertebrates,  P.  Blakiston's  Son  &  Co.,  Phila., 

1906. 
Kennedy,  R.:  On  the  restoration  of  co-ordinated  movements  after  nerve  crossing,  with  the 

interchange  of  function  of  the  cerebral  cortical  centers,  Roy.  Soc.  Proc,  v.  67:  1900, 

p.  431,  (.Abstract)  Phil.  Trans.,  B.  v.  194:  190,  pp.  127-162. 
Key,  a.  and  Retzius,  G.:  Studien  in  der  Anatomie  des  Nervensystems,  Stockholm,  Samson 

and  Wallin,  1875-76. 
Kraus,  W.  M.  and  Ingham,  S.  D.:  Electrical  stimulation  of  peripheral  nerves  exposed  at 

operation,  J. A.M. A.,  v.  74:  1920,  (Feb.  28),  p.  586. 
Peripheral   nerve   topography.      Seventy-seven  observations  of  electrical  stimulation  of 

normal  and  diseased  peripheral  nerves,  Arch.  Neurol.  &  Psychiat.,  v.  4:  1920,  pp.  259- 

296. 


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Langley,  J.  N.  and  Hashimoto,  M.:  On  ihc  suture  of  separate  nerve  bundles  and  on  inter- 
nal nerve  plexuses.      Jour.  Physiol.,  v.  51:   1917,  p.  318. 
Lantermanx,    a.  J.:  Ueber  den    feineren   Bau  der  markhaltigen   Xervenfasern,  Arch.  f. 

mikr.  Anat.,  v.  13:  1876,  p.  i. 
Marie,  Pierre:  Des  resultats  fournis  par  I'electrisation  directe  des  troncs  nerveu.x  dans  la 
plaie  operatoire  chez  les  blesses  atteints  de  traumatismes  des  nerfs,  Bull,  de  r.\cad.  de 
med.,  Par.,  ser.  3,  v.  72:  1915,  p.  173. 
Marie,  P.,  Gosset,  A.  et  Meige,  H.:  Les  Localisations  motrices  dans  les  nerfs  peripheriques, 

Acad,  de  Med.,  v.  3:  serie  74,  Dec.  28,  1915,  p.  798. 
MoRG.AN,  T.  H.:  Regeneration,  New  York,  Macmillan  Co.,  iqoi. 

Paterson,  A.  M.:  The  Anatomy  of  Peripheral  Nerves,  O.xford  Univ.  Press,  London,  1918. 
PiETRi,  G.  A.  and  Riquier,  G.  C:  Contributo  alia  determinazione  della  topogratia  fasciolare 

del  nervo  cubitale  al  braccio,  Chir.  d.  Organi.  di.  movimento,  v.  3:  1919,  p.  336. 
PuTTi,  v.:  Sulla  topografia  fascicolare  dei  nervi  periferici  e  piu  specialmente  dello  sciatico 

popliteo  esterno,  Chnica  chirurgica,  v.  24:  1916,  p.  1021. 
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No.  6,  December,  1912,  p.  487. 
R.-v.v\iER,  L.  A.:  Traite  technique  d'histologie.     Lecons  sur  I'histologie  du  systeme  nerveux 

Paris,  F.  Savy,  1875. 
Schmidt,  H.  D.:  On  the  construction  of  the  dark  or  double-bordered  nerve-fiber,  Monthly 

Microscopical  Journal,  v.  11:   1874,  p.  200. 
ScHULTE,  H.  W.  and  Tilney,   Frederick:  Development  of  the  neuraxis  in  the  domestic 
cat  to  the  stage  of  twenty-one  somites,  .\nnals  N.  Y.  Acad,  of  Sc.  v.  24:  1915,  p.  319. 
Sherrington,  C.  S.:  On  the  anatomical  constitution  of  nerves  of  skeletal  muscles;  with 
remarks  on  recurrent  fibers  in  the  ventral  spinal  nerve-root,  J.  Physiol.,  v.  17:   1894, 
p.  211. 
Stoffel,  A.:  Neue  Gesichtspunkte  auf  dem  Gebiete  der  Nerventransplantaton,  Zlschr.  f. 
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orthopad.  Chir.,  v.  30:   1912,  p.  177. 


CHAPTER  II 
NERVE  DEGENERATION  AND  REGENERATION 

The  numerous  contributions  dealing  with  the  question  of  degeneration  and 
regeneration  of  severed  or  injured  peripheral  nerves,  and  the  correlated  question 
of  the  development  of  peripheral  nerves,  evidence  the  importance  of  the  subject 
and  the  interest  taken  therein.  Laboratory  experimentors  and  clinicians  have 
contributed  to  this  extensive  literature,  and  there  is  perhaps  no  field  in  medicine 
in  which  the  interdependence  of  experimental  and  clinical  work  is  so  clearly 
demonstrated. 

Attention  was  drawn  to  this  subject  as  early  as  the  latter  part  of  the  iSth 
century,  when  Arnemann  (1787)  recognized  the  fact  that  the  peripheral  part 
of  a  divided  nerve  lost  its  conductivity  and  normal,  glistening  appearance  while 
the  central  stump  retained  its  irritability  and  glistening  appearance,  and 
Cruikshank  (1795)  and  Haighton  (1795)  reported  on  ingenious  experiments 
bearing  on  loss  of  function  and  its  repair  in  a  divided  peripheral  nerve.  The 
experiments  recorded  by  these  two  observers  were  similar  and  were  reported 
about  the  same  time  and  independently.  Both  observers  found  that  on  cutting 
the  vagosympathetic  trunk  in  the  neck  of  a  dog  on  both  sides,  death  followed 
wuthin  a  few  days,  while  if  this  nerve  was  severed  only  on  one  side  and  the 
animal  allowed  to  recover,  the  second  nerve  could  be  cut  some  weeks  later 
without  death  of  the  animal;  showing  a  recovery  of  function  of  the  lirst  nerve 
cut.  A  histological  study  of  a  peripheral  nerve  with  loss  of  conductivity 
after  injury  was  not  undertaken  until  nearly  fifty  years  later,  when  Nasse 
(1839)  recognized  and  first  described  a  fragmentation  of  the  medullary  sheath 
in  the  peripheral  portion  of  a  nerve  after  section  and  noted  the  ultimate  dis- 
appearance of  the  medullary  layer  and  the  neuraxis  of  the  peripheral,  injured 
nerve  fiber;  though  it  was  not  until  1852  that  Waller  clearly  demonstrated 
that  when  continuity  is  severed  in  a  peripheral  nerve,  the  portion  separated 
from  the  ganglion  cell"  undergoes  secondary  degeneration,  in  recognition  of 
which  we  have  spoken  of  this  phenomenon  as  Wallerian  degeneration.  Waller 
regarded  the  central  cell  as  the  nutritive  center  and  believed  that  the  part 
degenerated  was  replaced  by  outgrowth  from  the  center,  on  regeneration  of  the 
peripheral  portion.     Some  years  later  Ranvier  (1871-78)  and  still  later  Vanlair 

41 


42  SURGICAL   AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

(1882-85)  in  a  series  of  contributions  extended  our  knowledge  concerning  this 
subject,  more  particularly  as  concerns  the  down  growth  of  the  central  fibers 
in  the  process  of  nerve  regeneration.  However,  the  views  of  Waller  were 
not  universally  accepted.  Philipeaux  and  Vulpian  (1859-60)  after  extended 
resection  of  a  peripheral  nerve  in  young  animals,  found  the  peripheral  segment 
regenerated  after  a  period  of  several  months,  and  this  without  apparent  union 
with  the  central  stump,  and  believed  to  have  demonstrated  the  possibility  of 
autoregeneration — regeneration  of  the  peripheral  stump  in  and  of  itself.  There 
were  other  observers  (Schiff,  Erb,  Wolberg)  who  maintained  that  the  neuraxes 
of  the  nerves  of  the  peripheral  stump  did  not  undergo  degeneration,  but  re- 
mained intact. 

Thus,  just  prior  to  about  1890,  three  main  views  were  current  in  literature 
as  concerns  the  question  of  degeneration  and  regeneration  of  a  severed  peri- 
pheral nerve:  (i)  The  view  of  Waller,  that  after  secondary  degeneration  of  the 
peripheral  stump,  new  neuraxes  grew  out  from  the  central  end;  (2)  that  after 
secondary  degeneration,  the  new  neuraxes  developed  in  the  peripheral  stump 
and  were  secondarily  united  to  the  neuraxes  of  the  central  end;  (3)  that  the 
neuraxes  of  the  peripheral  stump  did  not  degenerate,  or  only  incompletely  so, 
and  might  in  time  unite  again  with  those  of  the  central  end.  In  the  years 
following  1890  there  appeared  a  series  of  monographic  contributions  dealing 
with  de-  and  regeneration  of  peripheral  nerves,  each  based  on  extensive  experi- 
mentation, controlled  by  careful  histological  studies.  These  contributions 
embrace  those  of  Biinger  (1891),  Howell  and  Huber  (1892),  Stroebe  (1893), 
Huber  (1895);  they  may  be  said  to  mark  the  beginning  of  the  modern  work 
on  nerve  degeneration  and  regeneration.  Biinger  (1891)  in  his  communication 
pointed  out  that  the  proliferation  of  the  sheath  cells  in  the  early  stages  of 
degeneration  took  place  by  means  of  mitotic  cell  division.  He  also  defined 
much  more  clearly  than  previous  workers  the  nucleated  protoplasmic  strands, 
the  "bandfasern'''  which  develop  within  the  old  sheaths  of  degenerating  nerves 
during  the  second  and  third  week  after  injury,  and  interpreted  them  as  embry- 
onic nerve  fibers,  built  up  from  a  chain  of  ectodermal  sheath  cells.  Within  the 
protoplasmic  bands  a  dehcate  longitudinal  striation  was  observed  and  re- 
garded as  indicating  development  of  neuraxes,  the  whole  evidencing  auto- 
regeneration in  the  peripheral  nerve  stump.  The  studies  made  by  Stroebe 
(1893)  were  based  on  observations  made  on  tissues  stained  after  his  specific 
neuraxis  stain,  and  by  use  of  his  method  he  believed  to  be  able  to  demonstrate 
down  growth  of  the  neuraxis  from  the  central  stump.     Huber  (1895),  using 


NERVE  DEGENERATION  AND  REGENERATION  43 

Stroebe's  method  in  an  experimental  study  on  the  bridging  of  nerve  defects, 
was  able  to  demonstrate  down  growth  of  neuraxes  from  the  central  uninjured 
portion  of  the  nerve,  division  of  central  neuraxes,  bulbous  ends  on  down  growing 
fibers  and  down  growth  of  nerve  fibers  of  central  origin  through  tissues  and 
substances  not  nerve  fibers.  These  studies  were  followed  by  a  series  of  con- 
tributions which  again  favored  the  possibility  of  autoregeneration  of  the 
peripheral  degenerated  nerve,  Galeoti  and  Levi  (1895),  Kennedy  (1897), 
Wieting  (1898).  In  summarizing  the  work  of  this  decade  it  may  be  stated 
that  there  prevailed  two  distinct  views  as  to  the  mode  of  degeneration  and 
especially  of  regeneration  of  severed  or  injured  peripheral  nerves;  (1)  A  mono- 
genetic  conception,  according  to  which  regeneration  of  the  peripheral  degen- 
rated  portion  of  a  nerve  is  obtained  through  down  growth  of  neuraxes  derived 
as  processes  of  central  neuraxes  at  all  times  connected  with  central  nerve  cells, 
and  (2)  a  polygenetic  conception,  according  to  which  regeneration  is  obtained 
through  the  mediation  of  cells  derived  from  both  the  central  and  peripheral 
stump,  which  cells  become  linked  to  form  a  continuous  nerve  fiber.  These 
opposed  views  existed  because  with  the  technical  methods  at  the  disposal  of 
workers  final  solution  could  not  be  reached  owing  to  the  fact  that  the  tissue 
elements  involved  could  not  be  differentially  stained,  and  this  applied  more 
particularly  to  the  staining  of  the  early  stages  of  growing  neuraxes. 

Recognizing  this  lack  of  adequate  technical  methods,  Bethe  (1903) 
attempted  to  bring  solution  to  this  problem  by  the  use  of  specially  devised 
experiments  in  which  he  attempted  to  separate  completely  portions  of  a  periph- 
eral nerve  from  central  connections,  which  peripheral  portions  were  weeks 
and  months  later  used  for  histological  study.  In  these  experiments  the  sciatics 
of  very  young  dogs  were  used,  and  these  were  either  grasped  at  the  sacrosciatic 
foramen,  torn  out  with  roots  and  ganglia  and  cut  in  the  middle  of  the  thigh,  or 
extensively  resected  in  the  middle  of  the  thigh  and  the  central  end  turned  into 
muscle  and  there  sutured.  Carefully  conducted  physiological  tests  and  autopsy 
studies  seemed  to  exclude  down  growth  of  nerve  fibers  from  the  central  to  the 
peripheral  stump.  Studies  of  the  peripheral  stump,  supposedly  completely 
separated  from  central  connection,  revealed  the  presence  of  medullated  nerve 
fibers,  evidencing,  it  was  thought,  autoregeneration  in  the  peripheral  end  of  the 
resected  nerve.  The  experiments  of  Bethe  appeared  convincing  and  excited 
much  interest;  however,  they  have  not  received  confirmation  and  have  in  the 
main  been  refuted  by  careful  experimental  observations  of  Langley  and  Ander- 
on  (1904),  Lugaro  (1905)  and  others. 


44  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Two  lines  of  work  have  been  instrumental  in  bringing  solution  to  this 
problem:  (i)  Studies  on  the  histogenesis  of  the  nervous  system  and  peripheral 
nerves  and  especially  certain  studies  in  experimental  embryology;  and  (2)  the 
development  of  modern  silver  methods  for  the  differential  staining  of  neuraxes 
of  nerve  fibers  and  especially  young  and  growing  neuraxes. 

The  histogenesis  of  neurones  has  been  a  subject  much  discussed,  particu- 
larly as  relates  to  the  development  of  peripheral  nerves  and  their  constituent 
parts.  Of  the  current  interpretations  of  the  mode  of  development  of  peripheral 
nerve  libers  the  one  more  commonly  accepted  is  the  out  growth  theory  of  His 
(1890).  According  to  this  theory,  the  nerve  fiber,  more  particularly  the 
neuraxis,  is  regarded  as  an  out  growth  of  a  single  cell.  This  cannot  be  demon- 
strated in  adult  tissue,  but  admits  of  near  demonstration  in  early  embryonic 
stages.  During  the  past  two  decades  the  wide  application  and  development 
of  special,  differential  neuraxis  staining  methods,  applicable  more  especially  to 
embryonic  tissue  and  extensively  used  by  Cajal  and  others,  have  gone  far 
to  demonstrate  and  establish  the  out  growth  theory  of  the  developing  nerve 
fiber.  This  theory  was  further  very  substantially  confirmed  through  the 
experimental  observations  of  Harrison  (1907),  who  was  able  to  observe  isolated 
ganglion  cells,  taken  from  the  spinal  cord  of  amphibian  embryos  and  cultured  in 
coagulated  lymph,  send  forth  neuraxis  processes,  these  showing  end  tips  and 
bulbs,  and  division  much  as  observed  in  the  developing  embryos.  Developing 
neuraxes,  as  observed  in  sections  of  suitable  stages,  are  from  the  beginning 
found  accompanied  and  closely  associated  with  cellular  elements,  regarded  by 
earlier  observers  as  of  mesodermal  origin,  by  more  recent  observers  quite 
clearly  shown  to  be  ectodermal  derivations,  and  variously  thought  of  as  differ- 
entiating to  form  sheath  cells  or  participating  in  the  formation  of  the  neuraxis 
itself.  The  presence  of  these  cells  led  to  the  formulation  of  the  so-called  "chain 
theory"  of  the  development  of  peripheral  nerves  with  which,  among  others, 
the  names  of  Balfour  (1875),  Dohrn  (1901),  and  later  Bethe  (1903)  are  asso- 
ciated. According  to  this  theory  each  nerve  is  thought  to  be  the  product  of  a 
chain  of  cells,  extending  from  the  nerve  center  to  the  peripheral  end  organ. 
The  study  of  sections  alone  did  not  seem  sufficient  to  enable  final  solution  of 
this  problem.  In  its  solution,  experimental  embryology  was  called  to  aid  by 
Harrison  (1906).  This  observer  was  able  to  ablate  the  dorsal  portion  of  the 
developing  spinal  cord  and  neural  crest  in  very  young  amphibian  embryos, 
thus  removing  the  anlage  of  the  dorsal  spinal  ganglia,  without  injuring  the 
ventral  portion  of  the  spinal  cord,  the  seat  of  the  cell  bodies  of  the  ventral  root, 


NERVE  DEGENERATION  AND  REGENERATION  45 

motor  fibers.  In  due  time  certain  ventral  root  fibers  were  found  to  develop, 
but  were  found  to  be  devoid  of  sheath  cells.  There  were  further  experiments 
on  amphibian  embryos  in  which  developing  limb  buds  were  transplanted,  which 
later  gave  evidence  of  neurotization,  indicating,  it  was  thought,  that  there  does 
not  of  necessity  exist  a  primary  connection  between  central  nerve  cell  and 
peripheral  end  organ  as  is  postulated  in  other  hypotheses  concerning  the 
development  of  peripheral  nerve  fibers,  Held  (1909).  The  results  of  these 
experimental  embryologic  observations  of  Harrison  and  others  have  been 
summarized  as  follows  (Streeter,  1912):  "  It  was  shown  that  no  peripheral 
nerve  fibers  would  develop  in  an  embryo  from  which  the  nerve  centers  had  been 
removed,  thus  establishng  the  fact  that  the  gangUon  cells  are  an  essential 
element  of  the  nerve  fibers.  It  was  shown  that  the  sheath  cells  of  Schwann, 
upon  the  influence  of  which  in  the  formation  of  the  fibers  many  of  the  his- 
tologists  had  placed  much  emphasis,  were  not  essential  to  the  growth  of  the 
nerve  fiber,  and  that  the  axis  cylinders  will  develop  and  extend  out  in  the 
surrounding  tissues  in  the  normal  way  and  reach  their  normal  length  in  speci- 
mens where  the  sheath  cells  have  been  eliminated.  It  was  shown,  by  modify- 
ing the  environment  of  the  developing  nerve,  that  fibers  will  form  in  surroundings 
entirely  different  from  their  natural  path  and  establish  completely  foreign 
connections." 

These  histogenitic  and  experimental  embryonic  observations  have  con- 
tributed much  to  bring  clarity  to  the  problem  of  nerve  de-  and  regeneration 
and  to  weaken  the  position  of  the  advocates  of  the  polygenetic  theory  of 
nerve  regeneration.  The  marked  improvement  in  technical  methods  in  rela- 
tively recent  years  has  assisted  greatly  in  furthering  our  knowledge  of  de- 
and  regenerating  peripheral  nerve  fibers.  The  silver  methods  of  Cajal,  of 
Bielschowski  and  of  Ranson,  permit  of  sharp  dift"erential  staining  of  neuraxes, 
especially  young  and  growing  neuraxes,  and  have  thus  enabled  a  more  precise 
study  of  the  fate  of  the  neuraxis  of  a  degenerating  nerve  and  of  the  reappearance 
and  growth  of  the  neuraxis  in  a  regenerating  nerve.  In  experimental  observa- 
tions controlled  by  careful  histological  studies,  using  differential  neuraxis 
staining  with  modern  silver  methods,  it  has  been  possible  to  follow  step  for  step 
the  neurotization  of  the  degenerating  or  degenerated  peripheral  stump  through 
down  growth  of  centrally  derived  neuraxes.  Quite  an  extensive  literature, 
based  on  observations  made  with  the  aid  of  differential  neuraxis  staining 
methods,  is  already  at  hand.  This  literature  includes  contributions  by  Per- 
roncito    (1907),    Poscharissky    (1907),    Cajal    (1908),    Ranson    (1912),    Boeke 


46  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

(i9i6-i7),Dustin  (1917),  Ingebrigtsen  (1918)  and  others.  Practically  all  the 
observers  who  have  used  the  modern  silver  methods  of  staining  the  neuraxes 
have  become  exponents  of  the  monogenetic  theory  of  nerve  regeneration. 
In  such  silver  preparations  there  are  present  no  appearances  which  would 
suggest  transition  stages  in  the  development  of  neuraxes  from  the  nucleated 
protoplasmic  bands  as  was  first  clearly  taught  by  Biinger  and  stated  by  other 
adherents  of  the  polygenetic  theory  of  nerve  regeneration;  on  the  other  hand, 
clearly  defined,  fine  neuraxes  may  often  be  observed  in  the  proximal  end  of 
degenerating  nerve  fibers,  before  the  nucleated  protoplasmic  bands  have 
fully  developed,  if  the  approximation  of  the  ends  of  a  divided  nerve  has  been 
good.  The  growing,  bulbous  ends  of  the  new  neuraxes  in  a  regenerating  nerve 
are  found  directed  toward  the  periphery,  in  the  distal  part  of  a  divided  nerve 
and  not  toward  the  wound  as  might  be  expected  in  autoregeneration  of  the 
distal  stump.  Further,  it  has  been  observed  that  there  is  a  great  over-produc- 
tion of  neuraxes  due  to  the  fact  that  a  number  of  branches  may  arise  from  a 
single  central  neuraxis,  and  old  sheaths  of  peripheral  degenerated  fibers  are 
often  found  to  contain  a  number  of  newly  formed  neuraxes,  difficult  to  explain 
on  the  theory  of  autoregeneration.  These  silver  methods  have  enabled  a  care- 
ful study  of  the  nonmedullated  fibers  in  degeneration  and  regeneration,  Ranson 
(1912),  a  study  not  possible  with  other  staining  methods. 

Studies  in  histogenesis  of  peripheral  nerves,  in  experimental  embryology 
dealing  with  the  development  of  peripheral  nerves,  and  the  more  recent  studies 
on  de-  and  regeneration  of  nerves,  warrant  the  conclusions  held  by  the  exponents 
of  the  monogenetic  theory,  beginning  with  Waller,  that  regeneration  of  a 
peripheral  degenerated  nerve  is  through  down  growth  of  out  sprouting  neuraxes 
of  the  central  end. 

The  titles  of  contributions  dealing  with  peripheral  nerve  de-  and  regener- 
ation number  now  several  thousand.  In  the  space  here  allotted,  few  could 
receive  special  mention  and  that  only  superficially.  Certain  of  these  cited  will 
in  succeeding  pages  receive  further  mention  in  the  brief  account  to  be  given  of 
the  present  day  views  concerning  peripheral  nerve  de-  and  regeneration. 

An  injury  producing  severance  of  continuity  in  a  peripheral  nerve  trunk, 
whether  induced  by  cutting  with  a  sharp  instrument,  by  laceration  of  tissues,  by 
crushing  or  by  chemical  agents,  calls  forth  a  series  of  structural  changes  in  the 
peripheral  segment,  spoken  of  as  secondary  degeneration,  and  involves  quite 
simultaneously  the  entire  length  of  the  nerve  fibers  distal  to  the  point  of  injury, 
except  for  a  narrow  zone  in  the  immediate  vicinity  of  the  wound,  a  zone  of  trau- 


NERVE  DEGENERATION  AND  REGENERATION 


47 


matic  injury,  varying  somewhat  in  width  with  the  character  of  the  injury,  but 
usually  not  found  wider  than  about  H  cm.  The  structural  changes  observed 
differ  in  medullated  and  nonmedullated  nerve 
fibers  and  need  thus  to  be  considered  separately. 

DEGENERATION  OF  MEDULLATED  NERVE  FIBERS 

Soon  after  injury  to  a  peripheral  nerve  and  for  a 
period  varying  from  one  to  several  days,  the  med- 
ullated nerve  fibers  distal  to  the  line  of  injury 
(except  in  the  immediate  vicinity  of  the  wound) 
present  no  demonstrable  structural  change  and  re- 
spond to  mechanical  and  electrical  stimulation. 
The  ensuing  structural  changes  are  first  demon- 
strable in  the  neurofibrils  of  the  neuraxes,  which 
present  varicosities,  and  this  is  soon  followed  by  a 
granular  breaking  down  of  the  neurofibrils,  Mon- 
ckeberg  and  Bethe  (1899).  In  pyridine  silver 
preparations  an  irregularity  of  the  contour  of 
the  neuraxes  is  observed  and  an  inequality  of 
staining,  Ranson  (1912).  Changes  in  the  myelin 
sheath  are  observed  in  certain  of  the  medullated 
fibers,  beginning  with  the  fourth  day  after  injury 
(dog,  and  probably  man;  second  or  third  day  in 
rabbit  and  guinea-pig).  These  changes  in  the 
myelin  are  first  recognized  as  irregularly  spaced 

enlargements  and  constrictions,  giving  to  the  fiber  Silver  preparation.    The  medul- 

.  .  lary  sheatli  is  found  in  segments 
a  varicosed  appearance.  This  is  followed  by  seg-  ^^rying  in  length,  a,  Long  seg- 
mentation or  fragmentation  of  the  myehn  sheath  me"'  "f  myelin  containing  h,  por- 

.         .  tion     of     neuraxis     in     granular 

and  soon  after  the  neuraxis,  resulting  m  the  for-  degeneration;  d,  sheath  or  neuro- 

mation  of  segments  of  unequal  length,  found  within    lemma  cells  in  process  of  prolifera- 

,  tion;   e.  connective   tissue   cell;/, 

the  neurolemma    sheath   and    known   as  myelin    ^hort  neuraxis  fragment.    (Cajal, 

ellipsoids.     Such  myelin  ellipsoids  usually  present    Trabajos   del  lab.  de  Investiga- 

,     ,  .  ,  .  clones  Biol.,  igo6.) 

rounded  ends  with  the  layer  ot  myehn  extending 

around  the  ends.     Within  such  segments  fragments  of  the  neuraxis  are  readily 

stained  in  silver   preparations,  and  the    neurokeratin    net  is  well  preserved 

and  readily  stainable  in  the  myelin  layer  surrounding  the  myelin  ellipsoids. 

Hand  in  hand  with  the  fragmentation  of  the  myehn  sheath  and  neuraxis,  of 


Fig.  iO. — Nerve  fibers  from  the 
peripheral  stump  of  the  sciatic  of 
a  rabbit,    5     days    after   section. 


48 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


the  degenerating  medullated  nerve  fibers,  there  is  observed  a  hypertrophy  of 
the  protoplasm  of  the  sheath  or  neurolemma  cells.  These  in  their  growth  in 
size  are  first  seen  to  press  on  and  constrict  the  myelin  and  neuraxis,  and  as 
these  fragment  and  the  pieces  draw  apart,  to  fill  the  en- 
tire sheath.  Both  the  protoplasm  and  the  nuclei  of  the 
sheath  cells  stain  more  deeply  and  nuclei  present  a  rich 
chromatin  content.  (See  Fig.  i6.)  In  the  succeeding 
few  days  there  is  observed  a  progressive  fragmentation 
of  myelin  ellipsoids,  resulting  in  the  formation  of  short 
segments  of  myelin,  or  oval  or  spherical  masses,  in  which 
small  masses  of  the  neuraxis  may  still  be  demonstrated 
with  silver  staining;  accompanying  this  there  is  to  be 
noted  a  marked  increase  in  the  protoplasm  of  the  sheath 
cells  and  a  proliferation  of  their  nuclei,  in  part  at  least 
by  means  of  mitotic  cell  division,  Biinger  (1891),  Huber 
(1892).  The  hypertrophied  protoplasm  of  the  sheath 
cells  encloses  and  surrounds  the  myelin  and  the  neur- 
axis remains.  By  the  end  of  the  first  week  after  injury 
to  a  peripheral  nerve,  nearly  all  of  the  nerve  fibers  of 
the  distal  stump  present  evidence  of  secondary  degen- 
eration, though  not  all  to  the  same  degree,  and  there 
are  a  certain  per  cent  of  medullated  fibers,  especially 
in  the  periphery  of  the  funiculi,  in  which  the  fragmenta- 
tion of  the  myelin  and  neuraxis  has  not  begun;  such  fibers 
persist  as  apparently  unaltered  fibers  into  the  second 
[  y  week  after  injury  to  the  nerve.     During  the  second 

I -.—Degenerating  week  alter  injury  to  the  nerve  there  is  observed  a  pro- 
nerve  fibers  of  the  peripheral  grggsive  fragmentation  of  mvelin  and  neuraxis  remains, 
stump    of   the    sciatic  of  a  ,,,',,  •  1  1 

rabbit,  10  days  after  section,   and  an  increase  in  the  sheath  cell  protoplasm  with  nuclear 

Silver  preparation,  a,  Sheath  proliferation.     (See  Fig.  17.)     The  myelin  is  now  found 
or     neurolemma     cells,    in- 
creased in  number  through  in  the  form  of  larger  and  smaller  globules,  surrounded 

proUferation;  h,  myelin  glo-  j^y  sheath  cell  protoplasm  which  exerts  a  phagocytic  ac- 


FlG 


bules;  c,  remains  of  neuraxis; 

d,    connective    tissue    cell,   tion  on  these  myeHn  remains. 


Toward  the  end  of  the 


(Cajal,  Trabajos  del  lab.  de   gecond  week  and  during  the  third  week  after  injury  to 
Investigaciones  Biol.,  igo6.) 

the  nerve,  the  myelin  globules  become  less  numerous 

and  the  protoplasm,  and  nuclei  of  the  sheath  cells  form  a  syncytical,  nucleated 

strand  of  protoplasm  found  within  the  old  neurolemma  sheaths,  and  containing 


NERVE  DEGENERATION  AND  REGENERATION  49 

here  and  there  larger  or  smaller  globular  remains  of  myelin.  These  nucleated 
protoplasmic  bands  of  protoplasm  were  tirst  fully  described  by  Bunger  (1891), 
and  in  literature  have  been  known  as  the  ''BaiidJ'aseni"oi  Biinger.  They  were 
observed  and  described  quite  independently  by  Howell  and  Huber  (1892)  and 
designated  as  embryonic  libers.  These  syncytial,  nucleated  protoplasmic 
bands,  the  product  of  the  hyperplasia  of  the  protoplasm  of  the  sheath  or  neuro- 
lemma cells  and  proliferation  of  their  nuclei  found  within  the  old  neurolemma 
sheaths,  in  both  meduUated  and  nonmedullated  nerve  fibers,  constitute  a  stage 
in  the  degeneration  of  the  nerve  fibers  of  the  peripheral  stump  of  an  injured 
nerve  that  persists  without  material  alteration  for  weeks  and  months.  Since 
the  sheath  cells  are  of  ectodermic  origin,  these  nucleated  protoplasmic  bands 
must  be  regarded  as  ectodermal  derivatives,  as  a  syncytial  nucleated  protoplasm, 
reverted  to  an  undifferentiated,  embryonic  state.  Some  time  after  their  forma- 
tion there  may  be  observed  a  delicate  longitudinal  striation  of  their  protoplasm. 
This  was  regarded  by  Bunger  (1891)  and  Bethe  (1903)  and  later  adherents  of 
the  polygenetic  school  of  nerve  regeneration,  as  indicating  neuraxis  develop- 
ment and  leading  to  autoregeneration  of  the  peripheral  nerve.  Even  in  silver 
preparations,  a  faint  longitudinal  striation  of  the  protoplasm  is  now  and  again 
observed,  but  no  observer  working  with  modern,  differential  neuraxis  staining 
methods  has  been  able  to  find  transition  stages  between  the  syncytial,  nucleated 
protoplasm  bands  and  neuraxes. 

The  removal  of  the  myelin  and  neuraxes  in  a  degenerating  peripheral  fiber 
has  been  the  subject  of  much  study  and  discussion.  The  fixed  and  wandering 
cellular  elements  of  a  peripheral  nerve  trunk  have  been  related  to  this  process 
in  one  way  and  another.  This  subject  has  received  extensive  consideration  by 
Doinikow  (1911),  using  various  differential  staining  methods  in  his  study. 
According  to  this  observer,  in  the  rabbit,  beginning  with  the  fragmentation  of 
the  myelin  the  second  day  after  injury  to  the  nerve,  there  may  be  found  fat 
droplets  in  the  protoplasm  of  the  sheath  cells,  which  are  thought  to  pass  to 
the  tissue  lymph  spaces  of  the  endoneurium,  probably  in  colloidal  solution. 
With  the  fourth  day  after  injury  of  the  nerve,  minute  fat  droplets  are  demon- 
strable in  the  mesodermal  cellular  elements  of  the  endoneurium,  and  by  the 
end  of  the  first  week  in  the  cellular  elements  of  the  perineurium.  In  the  period 
from  30  to  60  days  after  injury  there  may  be  noted  a  progressive  process  of 
removal.  The  ectodermal  elements  of  the  fiber  gradually  become  free  of  the 
products  of  degeneration,  while  the  number  of  the  fat  droplets  and  other  prod- 
ucts of  degeneration  in  the  " Bandfaseni"  become  fewer,  they  increase  in  the 


50  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

mesodermal   elements,    especially   lipoid   substances  stainable  in  Sudan  and 
Scharlach  R. 

DEGENERATION  OF  NONMEDULLATED  FIBERS 

The  account  here  given  of  the  mode  of  degeneration  of  the  nonmedullated 
nerve  fibers  of  a  peripheral  nerve  stump  after  injury  is  taken  from  Ranson 
(1912)  who  gave  us  the  first  accurate  description,  in  preparations  based  on 
pyridine  silver  staining.  Two  types  of  nonmedullated  fibers  are  recognized 
depending  on  the  rate  of  degeneration :  those  degenerating  during  the  first  week, 
which  are  thought  to  be  afferent,  nonmedullated  fibers,  the  peripheral  processes 
of  small  ganglion  cells  of  the  spinal  ganglia,  and  those  which  degenerate  during 
the  second  and  third  week,  looked  upon  as  efferent  nonmedullated  fibers,  the 
neuraxes  of  sympathetic  neurones.  In  the  former  type  the  neuraxes  begin  to 
degenerate  within  24  hours  after  injury  to  the  nerve.  They  first  become  gran- 
ular and  then,  after  two  or  three  days,  become  broken  into  segments  of  darker 
and  fighter  staining.  The  darker  segments  are  thought  to  represent  fragments 
of  the  neuraxis,  the  lighter  segments,  perhaps  fluid  exudate.  By  the  fourth  day 
the  darker  segements  begin  to  disintegrate  and  to  disappear  about  the  end  of 
the  first  week.  During  the  second  week  the  fibers  are  difficult  to  see,  but  pro- 
liferation of  the  sheath  nuclei  takes  place,  so  that  with  the  third  week  after 
injury,  fine  nucleated  bands  of  protoplasm  develop,  usually  seen  grouped  in 
rather  compact  small  bundles,  found  between  the  nucleated  protoplasmic 
bands  developed  from  the  medullated  fibers.  The  more  slowly  degenerating, 
efferent  nonmedullated  fibers  may  show  uniform  coloration  fourteen  days  after 
injury  to  the  nerve.  These  resistant  nonmedullated  nerves,  in  some  of  the 
pyridine  silver  preparations,  stand  out  cjuite  clearly  after  the  medullated 
and  less  resistant  nonmedullated  fibers  have  undergone  degeneration.  Their 
mode  of  degeneration  is  the  same  as  that  of  the  more  rapidly  degenerating 
nonmedullated  fibers.  "We  have,  therefore,  as  the  terminal  stage  of  the 
degeneration  of  the  nonmedullated  fibers,  nucleated  protoplasmic  bands  which 
differ  from  the  similar  bands  formed  from  the  medullated  fibers  only  in  size  and 
in  absence  of  myelin  droplets." 

DEGENERATION  OF  NERVE  ENDINGS.     MUSCLE 

A  number  of  observers  have  endeavored  to  follow  the  behavior  of  the  motor 
terminations  in  striated  muscle,  during  the  degeneration  of  a  peripheral  nerve. 
Of  these  Tello  (1907)  and  Boeke  (19 16)  have  used  differential  silver  staining. 

The  account  here  given  follows  the  excellent  studv  of  Boeke.     This  observer 


NERVE  DEGENERATION  AND  REGENERATION 


51 


found  that  changes  are  observable  in  the  neurofibrillar  net  of  the  end  plate 
during  the  first  day  in  that  these  fibrils  stain  very  lightly.  This  stage  lasts 
only  a  short  time  and  is  followed  by  one  in  which  the  fibrils  hypertrophy,  here 
and  there  agglutinate  and  stain  deeply.  This  hypertrophy  and  agglutination 
of  the  neurofibrils  proceeds,  in  the  course  of  the  next  day  or  two,  until  darkly 
staining  irregular  strands,  thicker  than  the  normal  divisions  of  the  nerve 
branches  of  the  ending,  are  found.  These  clump  and  appear  to  run  together 
and  then  fragment  to  form  irregularly  formed  stainable  masses  which  ultimately 
disappear.  The  periterminal  net  of  the  motor  ending  degenerates  a  short 
time  after  the  neurofibrillar  portion.  The  telolemma  nuclei  are  said  to  dis- 
appear and  there  is  noted  a  proliferation  of  the  sole  plate  nuclei,  probably  by 
amitotic  cell  division.  An  enlargement  of  the  sole  plate,  due  to  hypertrophy 
of  the  sarcoplasm  of  the  sole  plate  is  noted. 

The  degeneration  of  nerve  terminations  in  the  neuromuscular  and  neuror 
tendinous  end  organs  awaits  special  study  with  the  aid  of  differential  neuraxis 
staining  methods.  It  can  now  be  stated  that  the  neuraxes  disappear  completely 
in  these  endings. 

In  the  immediate  vicinity  of  the  wound,  approximately  within  5  mm.  of  the 
cut  surface,  in  the  distal  stump  certain  changes  are  observed  which  differ  from 
those  described  for  secondary  degeneration  both  for  medullated  and  non- 
medullated  nerve  fibers.  In  sections  of  tissue  including  that  portion  of  the 
distal  nerve  stump  adjacent  to  the  wound  in  the  nerve,  and  fixed  in  chromacetic- 
osmic  acid  mixture,  about  24  hours  after  injury,  the  myelin  sheaths  of  the 
medullated  nerves,  for  a  variable  distance,  do  not  color  black  in  the  osmic 
acid  as  do  normal  medullated  nerves,  but  present  a  granular  appearance. 
This  is  regarded  as  due  directly  to  the  traumatic  injury  inflicted.  The  neuro- 
lemma sheaths  often  appear  distended.  Polymorphonuclear  leucocytes  appear 
in  appreciable  numbers  between  the  nerve  fibers,  and  now  and  then  may  be 
seen  within  the  neurolemma  sheaths,  even  in  experiments  in  which  a  sharp 
knife  and  strict  asepsis  were  used  at  the  time  of  injury.  The  changes  are  ob- 
served in  the  immediate  vicinity  of  the  wound  at  a  time  when  the  nerve  fibers^ 
at  a  distance  of  about  i  cm.  from  the  wound  and  for  the  remainder  of  the  distal 
stump,  show  no  structural  change  or  alteration  in  conductivity.  In  prepara- 
tions of  the  distal  stump  in  the  wound  region,  stained  with  differential  neuraxis 
methods,  Perroncito  (1907),  Cajal  (1908),  Ranson  (1912)  and  others  noted 
both  in  medullated  and  nonmedullated  fibers  what  is  regarded  as  an  abortive 
autoregeneration,  consisting  of  temporary  side  branches  ending  in  bulbous  ends. 


52  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

This  phenomenon  is  observed  in  certain  nonmedullated  fibers  during  the  first 
day  after  injury,  consisting  in  side  branches  of  the  neuraxis,  ending  in  larger 
or  smaller  discs.  Such  branches  are  often  quite  numerous.  They  do  not 
show  much  growth  after  their  first  appearance,  and  the  majority  disappear 
during  the  first  week  after  injury,  though  on  certain  of  the  resistant  fibers  they 
may  persist  a  few  days  longer.  A  somewhat  similar  neuraxis  reaction  is  to  be 
observed  on  certain  of  the  medullated  fibers,  in  the  distal  wound  region,  per- 
haps in  the  more  resistant  fibers,  and  persists  after  neuraxis  degeneration  is 
observed  in  the  majority  of  the  medullated  fibers.  The  peripheral  end  of  the 
central  stump  of  a  divided  or  injured  nerve  degenerates  centralward  for  a  dis- 
tance that  varies  somewhat  with  the  character  of  the  injury,  but  generally  for  a 
distance  of  approximately  5  mm.  The  degenerative  changes  observed  here  are 
essentially  the  same  as  those  noted  in  the  peripheral  stump,  both  in  the  immedi- 
ate vicinity  of  the  wound  and  distal  thereto.  They  are  no  doubt  primarily 
largely  the  result  of  traumatism  inflicted  on  the  nerve  at  the  time  of  injury- 
Kirk  and  Lewis  (1917)  believe  that  there  is  an  early  hyperplastic  reaction  of 
the  neurolemma  sheaths,  adjacent  to  the  fine  of  section,  first  noticed  as  an 
increase  of  protoplasm  surrounding  the  sheath  nuclei,  followed  by  proliferation 
of  the  nuclei  by  mitosis,  so  that  between  the  fourth  and  sixth  days  proto- 
plasmic bands  have  become  well  developed.  Ranson  was  the  first  to  de- 
scribe fully  the  changes  to  be  noted  in  the  nonmedullated  nerves  in  the  distal 
portion  of  the  central  stump.  An  early  abortive  regeneration  was  noted  by 
this  observer.  This  is  analogous  to  the  abortive  regeneration  noted  for  the 
central  end  of  the  distal  stump,  and  consists  in  the  formation  of  lateral  branches 
during  the  first  24  hours  after  injury,  in  the  last  0.3  mm.  of  the  proximal  stump. 
These  lateral  branches  may  end  in  cylindrical  end  bulbs.  They  do  not  appear 
to  develop  much  after  their  first  appearance.  In  silver  preparations  they  begin 
to  stain  less  deeply  with  the  third  day  and  appear  only  as  indistinct  shadows 
during  the  fourth  day.  The  fading  in  staining  reaction  is  coincident  with  the 
beginning  of  a  cellulipetal  degeneration  which  is  observed  in  the  nonmedullated 
fibers  beginning  with  the  third  day  and  extends  perhaps  2  cm.  centralward  in 
the  central  stump.  The  manner  of  the  degeneration  is  the  same  as  that 
described  for  the  nonmedullated  fibers  of  the  peripheral  stump,  the  intensity 
of  the  process  decreasing  rapidly  in  a  central  direction. 

In  preparations  stained  after  one  of  the  differential,  silver  neuraxis  stains, 
certain  neuraxis  phenomena  are  observed  in  the  medullated  fibers  in  the  region 
nearest  the  wound,  not  unlike  those  noted  for  the  most  proximal  portion  of  the 


NERVE  DEGENERATION  AND  REGENERATION  S3 

distal  stump,  and  may  thus  be  described  with  the  degenerative  changes.  In 
certain  of  the  medullated  fibers,  0.2  mm.  to  0.5  mm.  central  to  the  cut  surface, 
in  which  final  segment  a  disintegrated  portion  of  the  neuraxis  is  found,  a  zone 
of  reaction  is  observed  in  which  the  neuraxis  is  several  times  its  normal  thick- 
ness, and  stains  quite  deeply  owing  to  the  fact  that  there  is  present  a  dense, 
deeply  staining  neurofibrillar  reticular  network,  the  whole  within  the  old 
neurolemma  sheath,  the  myehn  having  degenerated.  In  some  of  the  medul- 
lated fibers  two  such  zones  of  reaction  are  to  be  noted.  There  is  further  ob- 
served what  Ranson  has  designated  a  fibrillar  dissociation,  due  to  an  accummu- 
lation  of  interfibrillar  substance  and  hypertrophy  of  neurofibrils.  Finely 
striated,  large  neuraxes,  which  fill  the  neurolemma  sheaths  and  form  large 
cylindrical  bulbous  ends,  are  found  in  suitable  preparations  in  sections  stained 
with  other  than  silver  methods.  Very  early  branching  of  the  neuraxes  in  the 
immediate  neighborhood  of  the  lesion  is  observed.  These  branches  may  grow 
into  the  exudate  beyond  the  sheaths  of  the  nerve  fibers,  often  ending  in  fine 
cylindrical  expansions,  with  the  fibrillar  substance  located  at  the  periphery,  or 
fine  branches  may  arise  from  the  surface  of  the  neuraxis,  within  the  sheaths, 
where  they  become  entangled  in  further  growth,  presenting  complex  skeins. 
It  seems  quite  evident  that  these  neuraxis  reactions  of  the  central  stump,  ob- 
served soon  after  the  lesion  and  in  the  immediate  vicinity  of  the  wound,  are 
in  the  central  stump  as  in  the  peripheral  to  be  regarded  as  abortive  regenerative 
changes,  thus  associated  with  the  degeneration  phenomena. 

The  behavior  and  ultimate  fate  of  the  neurolemma  sheaths,  during  degen- 
eration of  a  peripheral  nerve  fiber,  deserves  brief  consideration.  During  the 
early  stages  of  degeneration  while  the  protoplasm  of  the  neurolemma  or  sheath 
cells  shows  hypertrophy  and  the  nuclei  proliferatie  by  mitotic  cell  division, 
the  neurolemma  sheath  itself  appears  to  show  no  definite  structural  change. 
In  certain  silver  preparations  of  the  wound  region  of  a  peripheral  nerve 
injected  with  absolute  alcohol  into  the  living  nerve,  and  removed  within  six  to 
eight  days  after  injury,  a  very  dehcate  fibrillar  differentiation  was  noted  in  the 
neurolemma  sheaths  in  certain  preparations.  This  was  not  a  constant 
observation,  but  was  thought  to  indicate  a  fibrillar  and  not  a  homogeneous 
structure  of  the  neurolemma  sheaths  with  hypertrophy  of  the  fibrils  and  per- 
haps increase  of  interfibrillar  substance  during  the  early  stages  of  degeneration. 
In  cross  and  longitudinal  sections  of  the  peripheral  stump,  one  to  three  months 
after  injury  to  the  peripheral  nerve,  in  which  regeneration  has  not  taken  place, 
it  seems  possible  to  differentiate  a  membranous  sheath,  as  surrounding  the 


54  SURGICAL   AND    MECHANICAL   TREATMENT    OF   PERIPHERAL   NERVES 

nucleated  protoplasmic  bands,  developed  from  the  sheath  cell  protoplasm  and 
nuclei.  In  making  this  statement  it  must  be  admitted  that  we  possess  no 
differential  neurolemma  sheath  staining  method.  Such  a  sheath  is  most 
clearly  made  out  in  segments  of  degenerated  nerve  libers  in  which  myelin 
remains  in  the  form  of  myelin  globules  are  still  evident.  In  such  regions  of 
the  degenerated  nerve  fibers  a  delicate  sheath  surrounding  the  nucleated 
protoplasmic  strand  and  the  myelin  globules  is  clearly  to  be  observed  in 
both  cross  and  longitudinal  sections.  In  experimental  observations  12 
to  15  months  after  injury,  in  peripheral  nerves  completely  degenerated,  what 
is  regarded  as  contracted  neurolemma  sheaths,  surrounding  the  nucleated 
protoplasmic  bands,  are  thought  still  to  be  observable.  According  to  the 
observations  of  Cajal,  the  neurolemma  sheaths  are  said  to  disappear  several 
weeks  after  the  degeneration  of  the  myelin  and  neuraxes  of  the  peripheral 
nerves  and  the  formation  of  the  nucleated  protoplasmic  bands  is  well  estab- 
lished, these  bands  remaining  surrounded  by  a  fibrillar  sheath  of  connective 
tissue  origin,  the  fibrillar  sheath  of  Retzius  or  of  Henle.  That  deUcate  sheath 
structures,  either  of  ectodermal  origin,  neurolemma  sheath,  or  of  mesodermal 
origin — Retzius'  or  Henle's  sheath — surround  the  nucleated  protoplasmic 
bands  months  after  the  degeneration  of  a  peripheral  nerve  is  well  under  way 
seems  well  established  by  abundant  observation.  There  is  at  hand  no  evi- 
dence to  indicate  that  the  old  neurolemma  sheaths  function  in  the  new  fibers 
should  regeneration  ensue. 

REGENERATION  OF  A  PERIPHERAL  NERVE 
Long  before  the  process  of  secondary  degeneration,  which  leads  to  the 
formation  of  the  syncytial,  nucleated  protoplasmic  bands  in  both  the  central 
and  peripheral  segements  of  a  divided  nerve,  is  complete,  there  may  be  recog- 
nized the  initial  stages  of  the  process  of  regeneration.  A  topical  and  timely 
separation  of  the  two  processes  cannot  be  made,  since  they  may  occur  side  by 
side  in  the  same  fiber.  However,  a  separate  consideration  of  the  two  processes 
is  justified  not  only  for  the  sake  of  clearness  in  discussion,  but  since  in  essence  we 
are  dealing  with  two  distinct  processes.  The  fact  that  evidence  of  regeneration 
may  under  favorable  circumstances  be  recognized  in  fibers  not  completely 
degenerated  argues  directly  for  the  independence  of  the  two  processes.  Space 
does  not  permit  at  this  time  even  a  superficial  citation  of  the  various  views 
held  from  time  to  time  concerning  the  manner  of  regeneration  of  a  peripheral 
nerve  after  injury.  The  literature  is  very  extensive  on  this  subject.  The 
main  phases  in  the  interpretation  of  the  process  of  nerve  regeneration  were 


NERVE  DEGENERATION  AND  REGENERATION  55 

touched  upon  in  the  brief  review  of  the  literature  given  at  the  beginning  of  this 
chapter,  and  it  will  there  have  been  noted  that  with  the  introduction  of  the 
Cajal  silver  methods  and  modifications  permitting  of  differential  staining  of 
neuraxes  from  early  stages  of  development,  in  the  majority  of  the  experimental 
observations  dealing  with  the  problem  of  nerve  regeneration  in  which  these 
silver  methods  were  used,  the  out  growth  or  the  monogenetic  theory  of  the 
development  of  the  neuraxis  in  regeneration  has  been  adopted.  Boeke  (1916), 
one  of  the  more  recent  workers,  expresses  himself  as  follows:  "I  place  myself 
without  question  as  adopting  the  viewpoint  that  in  regeneration,  as  in  develop- 
ment of  embryonic  nerve  fibers,  the  regenerating  nerve  fibers  arise  exclusively 
through  out  growth  from  the  divided  nerves  of  the  central  stump,  which  enter 
the  peripheral  path  and  in  this  reach  their  peripheral  destination."  The 
studies  of  Perroncito  (1905),  Cajal  (1908),  Ranson  (1912),  Boeke  (1916-17), 
Kirk  and  Lewis  (1917),  Dustin  (1917)  Ingebritsen  (19 18),  have  been  especially 
helpful  in  bringing  clarity  to  this  subject.  In  each  of  these  studies  the  develop- 
ment of  the  neuraxes  in  regeneration  was  given  special  consideration  in  prepa- 
rations stained  with  differential  neuraxis  staining  silver  methods.  With 
them  may  be  grouped  Krassin  (1908),  who  successfully  used  the  intra  vitam 
methylene  blue  method  in  the  study  of  nerve  regeneration.  While  unanimity 
of  view  has  not  been  reached  on  all  points  there  is  agreement  in  recognizing 
as  a  sine  qua  non  of  regeneration  of  the  peripheral  degenerated  portion  of  an 
injured  nerve,  down  growth  of  neuraxes  of  central  origin.  The  application 
of  these  silver  methods  has  enabled  the  determination  that  there  is  not  a  dis- 
continuous regeneration  of  the  neuraxes  of  a  degenerated  peripheral  nerve  as 
contended  by  the  supporters  of  the  theory  of  peripheral  autoregeneration  or  the 
polygenetic  theory  of  nerve  regeneration.  These  more  modern  observa- 
tions have  confirmed  in  full  and  extended  the  work  of  a  group  of  observers 
working  some  25  years  ago  who  contended  for  down  growth  of  central  neuraxes 
in  nerve  regeneration.  One  quotation  may  be  permitted,  Huber  (1895),  who 
at  the  conclusion  of  an  extended  study  in  nerve  repair  after  loss  of  substance 
expressed  himself  as  follows:  '  The  regeneration  of  the  peripheral  end  (which 
always  degenerates  so  that  only  the  old  sheaths  of  Schwann  containing  a  band 
of  nucleated  protoplasm,  developed  from  the  hypertrophied  protoplasm  and 
proliferated  nuclei  of  its  fibers,  are  met  with)  is  the  result  of  an  out  growth  of 
a  new  axis  cylinder  from  the  undegenerated  axes  of  the  central  stump,  the 
budding  axes  following  the  paths  of  least  resistance."  Evidence  of  regenera- 
tion was  noted  in  the  distal  end  of  the  central  stump  by  Perroncito  (1907)  a 


50  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

few  hours  after  injury,  and  by  a  number  of  observers  within  24  hours,  in  the 
form  of  very  line  branches  given  off  from  the  central  neuraxes,  which  grow  out 
into  the  exudate  or  remain  within  the  old  neurolemma  sheaths,  this  in  the 
immediate  vicinity  of  the  lesion.      (See  Figs.  18  and  19.)     This  very  early  evi- 


FiG.  18. — End  of  the  central  stump  of  the  sciatic  of  a  cat,  23-2  days  after  section.  Silver  prepara- 
tion. A,  Fine  neuraxis  with  end  bulb;  B,  branching  neura.xis;  C,  neuraxis  not  as  yet  in  regenera- 
tion; D,  fibrillation  of  neuraxis;  E  and  F,  phenomenon  of  Perroncito;  G  to  A',  end  discs.  (Cajal 
Trav.  du  Lab.  de  Recher.  Biol.,  1907.) 


dence  of  regeneration,  which  involves  certain  of  the  medullated  nerves,  may  in 
part  degenerate  again,  in  any  event  progresses  slowly  for  a  number  of  days, 
while  the  degenerative  changes  involving  the  ends  of  the  cut  fibers  of  the  central 
stump  are  initiated  and  in  progress.  The  more  purposeful  regeneration  begins 
somewhat  later,  but  is  well  under  way  by  the  end  of  the  first  week  after  sever- 
ance of  nerve  continuity,  and  is  evidenced  by  side  branches  and  buds  from  the 
central  neuraxes,  given  off  somewhat  higher  on  the  fibers  than  are  the  earUest 


NERVE  DEGENERATION  AND  REGENERATION 


:>/ 


branches,  usually  several  tenths  of  a  millimeter  from  the  cut  ends.  By  use  of 
the  dilTerential  silver  staining  method  it  has  been  clearly  shown  that  from  a 
single  central  neuraxis  of  a  medullated  nerve  liber  numerous  branches  may  be 


Fig.  iq. — End  of  central  stump  of  the  sciatic  of  a  cat,  3  days  after  section.  Silver  preparation. 
A  and  B  indicate  region  of  the  beginning  of  regeneration  of  the  neuraxis,  B,  with  recurrent  branch; 
C,  larger  and  D,  smaller  end  disc;  a  and  b,  larger  and  smaller  end  discs;  c,  terminal  ring;  d,  end  disc 
with  terminal  branches.     (Cajal,  Trav.  du  Lab.  de  Recher.  Biol.,  1907.) 

given  oft",  the  number  varies  but  is  by  Ranson  (191 2)  estimated  as  high  as 
fifty  or  even  more  buds  or  side  branches  for  a  single  fiber.  This  marked 
increase  in  the  number  of  the  central  neuraxes  is  most  clearly  seen  in  cross 
sections  of  the  more  distal  portion  of  the  central  segment  of  a  divided  nerve, 
made  at  the  proper  level  and  two  to  three  weeks  after  injury,  in  preparation 


58 


SURGICAL   AXD   ilECHL^XICAL   TREATMENT    OF   PERIPHERAL   NERVES 


subjected  to  suitable  differential  silver  staining.  In  such  preparations  clearly 
differentiated,  fine  neuraxes,  in  varying  though  appreciable  numbers,  may  be 
seen  within  the  old  neurolemma  sheaths  often  surrounding  the  undegenerated 
portion  of  the  old  neuraxis.  These  newly  formed  neuraxes  grow  toward  the 
periphery  of  the  central  stump,  within  the  old  neurolemma  sheaths  in  the  form 
of  bundles  of  fine  fibers  having  in  the  main  a  parallel  course  and  in  longitudinal 


Fig.  20. — From  distal  portion  of  central  stump  of  sciatic  of  the  dog,  32  daj-s  after  section. 
Pj-ridine  silver  staining.  Shows  several  Perroncito  spirals,  a  number  of  large  end-discs,  and  branch- 
ing of  coarser  and  finer  newlj'  formed  neura.xes. 

arrangement.  Within  other  sheaths,  for  reasons  for  which  no  satisfactory 
explanation  has  yet  been  given,  the  budding  neuraxes,  instead  of 
presenting  a  more  or  less  parallel  longitudinal  course,  assume  a  spiral  or  coiled 
arrangement,  more  or  less  complexly  woven,  forming  larger  or  smaller  skeins, 
often  surrounding  a  portion  of  the  old  undegenerated  neuraxis.  These  complex 
spiral  structures  were  first  clearly  described  by  Perroncito  (1907).  (See 
Fig.  20.)  These  more  recent  observations,  made  with  the  use  of  silver  methods, 
confirm  and  extend  the  contributions  of  earlier  investigators  bearing  on  the 
division  of  central  neuraxes  during  regeneration,  recorded  by  Ranvier  (1878), 
Howell  and  Huber  (1892),  Stroebe  (1893),  Huber  (1895). 

The  new  neuraxes  present  smaller  or  larger  end  discs  or  end  bulbs  of  oval, 


NERVE  DEGENERATION  AND  REGENERATION  59 

pear-shape  or  cylindrical  form,  directed  for  the  most  part  toward  the  periphery, 
now  and  again  centralward.  In  the  spiral  complexes  many  end  discs  or  end 
bulbs  are  frequently  observed,  forming  a  part  of  the  spiral.  The  growing 
end  discs  or  end  bulbs,  found  on  the  out  growing  neuraxis  branches,  are  very 
similar  to  those  observed  in  the  developing  central  and  peripheral  nervous 
system  of  embryos,  and  the  growing  end  tips  and  end  discs  observed  by  Harrison 
in  tissue  culture  preparations  of  isolated  ganglion  cells  from  the  embryonic 
spinal  cord  of  frog  grown  in  clotted  lymph.  The  growing  end  discs  or  end 
bulbs  observed  in  silver  preparations  of  regenerating  nerves  are  often  quite 
large,  many  times  the  diameter  of  the  neuraxis,  and  it  is  conjectured  that  the 
size  of  the  end  disc  is  in  a  measure  proportionate  to  the  resistance  met  by  the 
down  growing  fibers. 

Ranson  (191 2)  has  determined  that  the  nonmeduUated  nerve  fibers  of  the 
central  segment  of  a  cut  nerve  begin  regeneration  about  the  fourteenth  day, 
after  the  abortive  regeneration  and  cellulipetal  degeneration  have  taken  place. 
There  occurs  a  down  growth  of  neuraxes  from  above  the  point  where  the  degen- 
eration ceases.  The  down  growing  neuraxes,  the  branches  of  the  non- 
meduUated fibers,  present  small  end  bulbs  and  are  arranged  in  quite  compact 
bundles.  Their  number  increases  in  the  distal  end  of  the  central  segment  of  a 
divided  nerve,  for  several  weeks  after  their  regeneration  begins.  It  seems 
quite  clear  that  there  is  formed  an  increased  number  of  nonmeduUated  fibers, 
through  branching  and  budding  of  the  central  nonmeduUated  fibers,  though 
this  is  not  easily  demonstrated  owing  to  the  compactness  of  the  bundles. 

The  branches  of  the  neuraxes  of  ijoth  the  medullated  and  the  nonmeduUated 
fibers,  when  first  seen,  appear  as  fine  nonmeduUated  fibers.  The  marked 
increase  in  the  number  of  these  fibers  was  not  appreciated  until  the  difierential 
neuraxis  staining  methods  with  silver  salts  were  available,  and  all  who  have  used 
these  methods  successfully  confirm  these  results.  These  observations  have  with 
justice  been  used  to  confirm  and  substantiate  the  theory  of  the  out  growth  ot  the 
neuraxis  in  nerve  regeneration.  The  practical  value  of  these  observations  will 
receive  consideration  in  the  following  pages. 

From  the  beginning  of  the  formation  of  branches  of  neuraxes  within  the 
neurolemma  sheaths  of  the  nerve  fibers  of  the  central  segment  of  a  divided 
nerve,  certain  of  the  branches  can  be  traced  into  the  exudate  and  debris  covering 
the  distal  end  of  the  central  stump.  Such  early  branching  of  the  neuraxes 
within  the  first  24  hours  after  injury  to  the  nerve  has  been  described,  par- 
ticularly by  Perroncito  and  Ranson,  as  arising  from  the  medullated  fibers.     The 


6o  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

increase  in  the  number  of  the  branching  fibers  reaching  the  exudate  over  the  end 
of  the  nerve  progresses  slowly  for  the  first  few  days  after  the  division  of  the  nerve, 
but  is  accelerated  toward  the  end  of  the  first  week  after  injury  by  which  time  the 
number  of  new  neuraxes  which  have  extended  beyond  the  limits  of  the  central 
fibers  and  cut  neurolemma  sheaths  is  quite  considerable.  Immediate  suture 
after  injury  does  not  appear  to  influence  the  rate  of  down  growth  of  neuraxes. 
As  the  new  neuraxes  leave  the  old  neurolemma  sheaths,  within  which  they  show 
in  the  main  a  quite  regular  arrangement,  and  reach  the  exudate  over  the  cut  end 
of  the  nerve  and  the  organizing  embryonic  connective  tissue,  whether  the 
nerve  was  sutured  or  not,  the  small  bundles  of  neuraxes  lose  their  regular 
arrangement  and  direction  parallel  to  the  long  axis  of  the  nerve,  and  assume  an 
irregular,  crisscross  course,  either  as  single  libers  or  small  bundles  of  fibers  as 
they  course  through  the  exudate  and  einbryonic  connective  tissue.  In  serial 
section  of  the  wound  region,  made  in  longitudinal  direction,  removed  one  to  two 
weeks  after  injury  and  stained  after  the  pyridine-silver  method,  fine  neuraxes  can 
be  traced  from  the  central  stump  into  the  organizing  scar  tissue,  in  which  they 
pass  in  all  directions,  their  number  and  the  distance  for  which  they  penetrate 
the  scar  varying  directly  with  the  length  of  time  after  the  injury  the  observation 
is  made.  In  such  preparation  it  is  not  possible  to  distinguish  between  neuraxis 
branches  derived  from  medullated  and  those  derived  from  nonmeduUated  fibers. 
There  is  often  noted  an  exchange  of  libers  between  small  adjacent  bundles  and  it 
is  not  difficult  to  observe  division  of  neuraxes,  usually  directed  toward  the 
periphery.  Now  and  again  a  fiber  may  be  traced  through  several  divisions  in 
the  same  or  successive  sections.  Neuraxes  terminating  in  end  discs  within  the 
organizing  scar  tissue  of  the  wound  are  to  be  observed  in  nearly  every  well- 
stained  preparation.  These  end  discs  have  in  general  a  direction  toward  the 
periphery,  others  are  found  directed  centralward  and  again  others  toward  the 
organizing  scar  tissue  surrounding  the  nerve  in  the  wound  region.  In  serial 
cross  sections  of  the  wound  region  removed  several  weeks  after  injury,  and  stained 
after  the  pyridine  silver  method,  it  may  be  observed  that  there  is  a  loss  of  the 
funicular  arrangement  of  the  nerve  as  represented  by  the  down  growing  neu- 
raxes, penetrating  the  organizing  scar  tissue  of  the  nerve  wound,  the  neuraxes 
passing  in  all  directions  and  often  for  a  considerable  distance  in  the  plane  of  the 
cross  section.  Serial  cross  sections  of  the  wound  region,  taken  at  suitable  stages 
and  stained  in  pyridine  silver,  are  also  instructive  in  showing  a  gradual  diminu- 
tion of  neuraxes  as  the  observer  passes  from  the  more  central  to  the  more  distal 
portion  of  the  wound  region. 


NERVE  DEGENERATION  AND  REGENERATION  6 1 

In  case  immediate  or  primary  suture  of  the  severed  nerve  has  taken  place, 
new  neuraxes  will  be  found  to  have  entered  the  distal  stump  only  a  few  days 
after  they  are  found  in  the  organizing  scar  tissue  of  the  wound  region.  Serial 
longitudinal  sections,  including  the  wound  region  and  approximately  i  cm.  of 
the  nerve  central  and  distal  to  the  wound,  taken  at  intervals  of  2  to  3  days 
during  the  hrst  three  weeks  after  injury  to  the  nerve,  and  stained  after  the 
pyridine  silver  method,  enable  the  observer  to  trace  step  for  step  the  formation 
of  the  neuraxes  branches  in  the  distal  end  of  the  central  segment  of  the  injured 
nerve,  their  gradual  penetration  of  the  organizing  scar  tissue  of  the  wound 
and  the  entrance  of  the  new  neuraxes  in  the  central  end  of  the  distal  segment. 
At  first  only  a  few  neuraxes  will  be  found  in  the  central  end  of  the  distal  seg- 
ment, their  number  increasing  directly  with  the  length  of  time  after  the  nerve 
injury  and  suture  the  observation  is  made.  Once  the  new  neuraxes  have 
penetrated  to  the  central  end  of  the  distal  segment,  their  course  becomes  again 
very  regular  and  parallel  to  the  long  axis  of  the  nerve.  In  both  cross  and  longi- 
tudinal sections  of  the  more  central  portion  of  the  distal  segment,  made  after 
central  neuraxes  have  reached  it,  it  can  readily  be  determined  that  at  first  only 
a  few  neuraxes  reach  the  distal  stump,  the  great  bulk  of  the  fibers  presenting  a 
stage  in  nerve  degeneration.  Under  favorable  conditions  new  neuraxes 
may  penetrate  to  the  distal  stump  before  its  nerve  fibers  have  reached  the  end 
stage  in  degeneration;  namely,  the  formation  of  the  syncytial,  nucleated  proto- 
plasmic bands.  It  is  not  unusual  to  observe  several  new  neuraxes  in  one  old 
neurolemma  sheath  in  the  distal  stump.  In  longitudinal  section,  neuraxes  with 
end  discs  are  often  noted,  indicating  termination  of  the  new  neuraxis  within  the 
limits  of  the  section.  Such  end  discs  or  end  bulbs  are  directed  toward  the 
periphery.  In  case  cross  and  longitudinal  serial  sections  are  made,  at  intervals 
of  the  distal  segment  of  an  injured  nerve,  after  regeneration  begins,  it  may 
readily  be  determined  that  new  neuraxes  are  found  first  in  the  immediate 
vicinity  of  the  wound,  while  beyond  a  certain  region  only  degenerated  fibers 
are  found,  and  where  it  is  possible  to  determine  clearly  the  ending  of  new 
neuraxes  in  the  distal  segment,  these  will  be  found  to  terminate  in  end  discs 
directed  toward  the  periphery.  The  area  of  neurotization  in  the  peripheral 
segment  of  a  divided  nerve,  after  the  initial  stage  of  regeneration,  is  estimated 
to  progress  toward  the  periphery  at  the  rate  of  i  to  2  mm.  in  24  hours. 
It  progresses  gradually,  not  only  in  the  depth  of  penetration  of  centrally 
derived  neuraxes,  but  also  in  the  general  increase  in  the  number  of  new 
neuraxes  which  reach   the  distal  segment;  the  number  of  the  new  neuraxes 


62  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

gradually  decreases  as  one  passes  from  the  region  of  the  wound  toward  the 
periphery.  Attention  has  been  called  to  the  very  great  increase  in  the  number 
of  neuraxes  formed  in  the  distal  portion  of  the  central  segment  of  a  divided 
nerve;  only  a  variable  percentage  of  these  reach  the  distal  segment,  propor- 
tionately more  the  more  favorable  the  path.  The  down  growing  neuraxes 
derived  from  the  central  segment  are  diverted  from  the  more  direct  path  toward 
the  periphery  by  the  organizing  scar  tissue  of  the  wound.  Numerous  neuraxes 
are  deflected  so  as  to  be  directed  toward  the  central  segment  into  the  endoneural 
tissue  in  which  they  may  grow  for  a  short  distance.  Others  are. directed  toward 
the  periphery  of  the  organizing  scar  tissue  of  the  wound  to  be  lost  in  the  con- 
nective tissue  surrounding  the  wound.  In  experimental  work  it  may  be  easily 
observed  that  the  more  successful  the  suture  the  earlier  may  down  growing 
neuraxes  be  found  in  the  central  end  of  the  distal  stump,  and  the  greater  propor- 
tion of  new  nerve  fibers  reach  the  distal  stump.  In  case  primary  suture  is  not 
made  and  the  severed  nerve  ends  are  not  in  close  approximation,  even  though 
there  be  not  extensive  loss  of  nerve  tissue,  the  down  growing  central  neuraxes 
become  dispersed  in  the  scar  tissue  forming  about  the  distal  end  of  the  proximal 
stump  and  penetrate  only  very  slowly  in  the  direction  of  the  periphery. 

As  has  been  stated,  the  down  growing  neuraxes  derived  from  the  central 
neuraxes,  whether  formed  as  branches  of  medullated  or  of  nonmedullated  nerve 
libers,  are  at  first  all  of  the  type  of  nonmedullated  nerve  libers.  They  penetrate 
the  tissue  of  the  wound  and  reach  the  central  end  of  the  distal  segment  as  non- 
medullated libers.  Whether  these  nonmedullated  new  neuraxes  are  preceded 
or  accompanied  by  sheath  cells  or  sheath  cell  derivatives,  the  syncytial 
nucleated  protoplasmic  bands,  has  not  been,  it  seems  to  me,  finally  deter- 
mined. The  modern  silver  staining  methods,  which  have  given  such  clear 
differentiation  of  growing  neuraxes,  do  not  stain  equally  clearly  nuclei  and  other 
protoplasmic  structures.  This  makes  it  difficult  and  quite  impossible  in 
such  preparations  to  differentiate  between  cells  derived  from  the  ectodermal 
sheath  cells  and  the  mesodermal  fibroblasts.  Both  types  of  cells  appear  to  form 
syncytial  structures  in  early  stages  of  prohferation.  Kirk  and  Lewis  (191 7) 
believe  to  have  shown  that  the  syncytial  nucleated  protoplasmic  bands 
constitute  conduits  in  the  substance  of  which  the  nonmedullated  nerve  fibers 
of  regeneration  from  the  proximal  stump  rapidly  grow  down,  the  bands  growing 
first,  the  fibers  following  along  them;  though  they  state  that  they  do  not  wish 
to  imply  ''that  the  axis  cylinders  always  and  necessarily  track  along  the  proto- 
plasmic bands."     It  is  difficult  to  conceive  of  the  large  growing  end  discs  or 


NERVE  DEGENERATION  AND  REGENERATION 


63 


end  bulbs,  thought  to  possess  amoeboid  properties,  found  at  the  end  of  growing 
neuraxes  as  within  the  nucleated  protoplasmic  bands.  The  same  may  be 
thought  concerning  the  complex  spiral  structures  and  the  numerous  neuraxes 
found  sprouting  from  a  single  central  neuraxis  of  a  medullated  fiber.     It  is 


Fig.  21. — Newly  formed  neuraxes  in  the  peripheral  stump  of  the  nerve  of  a  rabbit  27  daj-s  after 
section.     Silver  preparation,     a,  Interstitial  fibers  with  end  bulb;  6,  end  bulb  within  a  "bandfaser;" 

c,  d,  e,  g,  newly  formed  neuraxes  passing  to  one  side  of  myelin  remains  within  the  neurolemma  sheaths; 

d,  division  of  a  neuraxis;  /,  bundle  of  neuraxes  within  a  single  sheath.  (Cajal,  Trabajos  del  lab. 
de  Investigaciones  Biol.,  1906.) 

known  from  experimental  embryological  evidence  that  neuraxes  may  develop 
without  the  presence  of  sheath  cells,  and  it  has  been  the  contention  of  the  writer, 
based  on  negative  as  well  as  positive  evidence,  that  the  same  possibiUty  must 
be  ascribed  to  down  growing  neuraxes  in  nerve  regeneration.  What  appear 
to  be  naked  neuraxes  without  the  presence  of  sheath  cells  are  often  followed 
for  quite  long  distances  in  the  connective  tissue  sheaths,  sometimes  several 
centimeters  from  the  wound  region. 

A  number  of  authors  have  voiced  the  opinion  that  the  degenerating  fibers 


64  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

of  the  peripheral  stump,  more  particularly  the  syncytial  nucleated  protoplas- 
mic bands,  exert  a  chemiotactic  influence  on  the  down  growing  neuraxes, 
causing  them  to  bud  or  grow  in  the  direction  of  the  peripheral  stump.  So  far  as 
I  am  aware,  there  are  no  conclusive  experimental  observations  to  substantiate 
this.  On  reaching  the  central  end  of  the  peripheral  segment  the  down  growing 
neuraxes  are  found  to  penetrate  and  grow  into  the  old  neurolemma  sheaths  of 
the  degenerating  libers.  A  certain  number  are  also  to  be  found  in  the  endo- 
neural connective  tissue  between  the  degenerating  fibers  now  and  again  even  in 
the  perineural  and  epineural  sheaths.  The  relation  of  the  down  growing 
neuraxes,  found  within  the  old  neurolemma  sheaths,  to  the  syncytial  nucleated 
protoplasmic  bands,  the  end  result  of  degeneration,  has  been  differently  inter- 
preted by  observers;  as  playing  only  a  passive  role,  or  serving  as  conduits 
for  the  down  growing  neuraxes-  Ranson  (1912)  states  that  "all  new  axons  lie 
in  protoplasmic  bands,  never  between  them."  Boeke  (1916),  on  special 
study  with  various  methods,  reached  the  conclusion  that  the  neurofibril  strands 
are  always  intraprotoplasmic.  The  prevailing  opinion  at  the  present  time 
regards  the  down  growing  neuraxes  found  in  the  peripheral  neurolemma  sheaths 
as  having  intraprotoplasmic  position. 

So  far  as  has  been  determined  there  is  no  reason  to  assume  that  the  down 
growing  neuraxes  show  any  selectivity  on  reaching  the  peripheral  stump.  Thus 
branches  derived  from  the  central  neuraxes  of  motor  neurones  may  and  no  doubt 
do  enter  the  neurolemma  sheaths  of  peripheral  sensory  fibers,  and  branches  from 
central  afferent  nerves  into  distal  efferent  nerves,  and  no  doubt  branches  of  the 
central  nonmedullated  fibers  may  enter  distal  medullated  fibers,  either  motor 
or  sensory.  That  central  motor  fibers  may  grow  into  distal  sensory  fibers,  and 
vice  versa,  has  long  been  believed  and  has  recently  been  confirmed  in  an 
extensive  study  by  Boeke  (191 7).  Functional  regeneration  has  not  been  ob- 
tained under  such  conditions,  although  attempts  in  the  development  of  nerve 
terminations  have  been  noted. 

It  must  be  assumed  that  chance  brings  at  least  as  many  branches  of  central 
motor  neurones  as  of  the  sensory  neurones  to  peripheral  motor  degenerating 
fibers,  and  that  in  the  end  the  motor  fibers,  forming  contact  with  muscle  fibers 
and  ultimately  developing  new  motor  endings,  survive,  while  the  sensory  fibers 
entering  distal  motor  fibers,  not  forming  functional  connections,  degenerate.  So 
with  sensory  and  with  nonmedullated  fibers  of  the  central  stump,  such  of  these 
fibers  as  reach  equivalent  distal  fibers  regenerate  to  the  completion  of  end 
organs,  while  such  fibers  as  reach  heterogeneous  peripheral  fibers  ultimately 


NERVE  DEGENERATION  AND  REGENERATION  65 

degenerate.  The  enormous  increase  in  the  number  of  new  neuraxes  formed  in 
the  peripheral  end  of  the  central  stump  permits  many  new  liber  branches  to  go 
astray  in  the  scar  tissue  and  in  the  peripheral  stump  and  still  leave  a  sufiticient 
number  to  admit  of  structural  and  functional  regeneration.  It  has  seemed  to 
me  that  the  purely  mechanical  interpretation  is  more  nearly  in  accord  with 
observed  facts  than  any  other  that  could  be  given. 

Huber  (1900),  Tello  (1907)  and  Boeke  (1916)  have  studied  the  regeneration 
of  motor  and  sensory  nerve  terminations  in  striated  voluntary  muscle  tissue 
after  experimental  degeneration  of  nerves,  with  the  aid  of  differential  neuraxis 
stains  (methylene  blue  and  silver  staining  methods).  Experimental  observa- 
tions indicate  that  a  muscle  which  fails  to  respond  to  electrical  stimulation  of  its 
nerve,  degenerated  by  reason  of  interruption  of  its  continuity,  again  responds  to 
electrical  stimulation  as  soon  as  motor  endings  can  be  demonstrated  in  the 
muscle  with  suitable  stains.  Down  growing  neuraxes  can  be  demonstrated  in 
the  small  muscular  branches  within  the  muscle,  here  and  there  seem  to  end  in  end 
discs,  at  a  time  when  there  is  no  response  by  the  muscle  to  electrical  or  mechanical 
stimulation  of  the  nerve.  Developing  motor  endings  in  regeneration  have  been 
demonstrated  either  as  forming  by  branching  from  terminal  end  discs  or  as  end 
branches  of  collaterals,  led  to  the  muscle  fibers  within  old  neurolemma  sheaths, 
or  as  along  syncytial  strands  of  sheath  cells  or  possibly  also  along  cells  of  con- 
nective tissue  origin.  Boeke  (1916)  has  shown  that  there  is  often  an  over  pro- 
iluction  of  motor  endings  in  regeneration,  since  certain  muscle  fibers  may  show 
more  than  one  nerve  termination.  It  has  been  found  that  the  motor  nerve 
endings  regenerate  before  the  sensory  nerve  terminations  in  the  muscle.  Coarser 
and  finer  nonmedullated  nerve  fibers,  often  showing  branching,  may  be  observed 
within  the  fibrous  capsule  of  the  neuromuscular  and  neurotendinous  spindles 
before  the  characteristic  endings  can  be  demonstrated.  Complete  regeneration 
of  the  complex  neuromuscular  spindles,  so  far  as  concerns  the  nerve  termin- 
ations, has  been  observed.  For  the  study  of  these  endings  the  intra  vitam 
methylene  blue  method  appears  on  the  whole  to  give  more  satisfactory  results, 
in  case  positive  results  in  the  form  of  successful  staining  have  been  attained. 
Negative  results,  want  of  staining,  cannot  be  regarded  as  trustworthy,  owing  to 
the  precariousness  of  the  method. 

As  has  been  stated,  in  the  processes  of  regeneration  of  a  peripheral  divided 
nerve,  all  of  the  branches  of  the  central  neuraxes,  whether  derived  as  out 
growths  from  meduUated  or  from  nonmedullated  fibers,  appear  first  as  non- 
medullated fibers  and  as  such  penetrate  and  pass  through  intervening  scar 


66 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


tissue,  and  as  nonmedullated  neuraxes  enter  the  central  end  of  the  distal 
segment,  and  proceed  distalward  therein.  It  seems  quite  clear  that  formation 
of  the  medullary  or  myelin  sheath  of  libers  destined  to  become  medullated 


Fig.  22.— The  proximal  end  of  the  peripheral  nerve  of  a  cat  72  days  after  section.  Silver 
preparation.  The  neurotization  of  the  peripheral  stump  was  delayed.  The  figure  shows  division  of 
a  number  of  neura.xes,  a,  b,  c,  and  d,  after  passing  the  wound  and  reaching  the  nerve  fibers  of  the 
distal  stump;/,  terminal  end  discs.     (Cajal,  Trabojos  del  lab.  de  Investigaciones  Biol.,  1906.) 

fibers  proceeds  distalward,  beginning  with  the  proximal  end  of  the  divided 
nerve.  The  manner  of  the  development  of  the  medullary  sheath,  both  as  con- 
sidered in  histogenesis  and  in  a  regenerating  nerve  fiber,  has  not  been  finally 
determined.  Two  general  views  have  prevailed:  First,  that  the  medullary 
sheath  is  the  product  of  the  neurolemma  or  sheath  cells;  second,  that  it  repre- 


NERVE  DEGENERATION  AND  REGENERATION  67 

sents  a  differentiation  of  the  outer  portion  or  layer  of  the  neuraxis.  In  the 
more  recent  studies  of  de-  and  regeneration  of  peripheral  nerves,  with  the  aid 
of  differential  neuraxis  stains,  the  study  of  the  development  of  the  neuraxes 
has  been  given  prime  consideration.  The  methods  used  have  not  been  suitable 
for  the  study  of  the  development  of  the  medullary  sheath.  The  medullary 
sheath  can  be  recognized  first  in  the  newly  formed  fibers  of  the  proximal  seg- 
ment of  a  divided  nerve,  toward  the  end  of  the  first  month  of  the  injury,  in 
the  form  of  a  very  delicate  sheath,  not  recognized  in  silver  preparations  but 
brought  out  in  chromatized  tissue  followed  by  differential  myelin  staining. 
The  structural  appearance  presented  suggests  differentiation  of  the  medullary 
or  myelin  sheath  from  the  peripheral  layer  of  the  neuraxis,  though  this  has  not 
been  definitely  determined.  Medullary  sheath  formation  proceeds  distalward 
relatively  slowly,  and  does  not  involve  all  of  the  nerve  fibers  at  the  same  time. 
Medullary  sheath  formation  begins  in  the  proximal  segment  of  the  divided 
nerve  before  functional  connections,  in  the  form  of  nerve  terminations,  have 
had  opportunity  to  develop.  Whether  myelin  formation  is  dependent  on  the  age 
of  the  fiber,  or  whether  other  factors  play  a  part,  cannot  at  present  be  stated. 

It  would  seem  quite  clear,  although  this  has  not  been  definitely  determined, 
that  the  neurolemma  sheaths  of  the  new  fibers  are  new  formations,  developed 
from  the  sheath  cells  wandering  out  from  the  distal  end  of  the  proximal  stump 
or  found  in  situ  by  the  down  growing  neuraxes,  the  result  of  sheath  cell  prolif- 
eration during  nerve  degeneration. 

NERVE  TRANSPLANTATION 

An  endeavor  has  been  made  in  the  preceding  pages  to  make  clear  the  fact 
that,  according  to  the  prevailing  view,  regeneration  of  the  distal  segment  of  a 
divided  peripheral  nerve  is  due  entirely  to  the  down  growth  of  neuraxes  from 
the  proximal  segment,  and  that  the  down  growing  neuraxes  reach  the  proximal 
end  of  the  distal  segment  in  a  relatively  short  period,  if  proper  approximation 
of  the  divided  nerve  ends  is  attained  and  maintained  by  suture.  In  case  an 
adequate  approximation  of  the  divided  nerve  ends  is  not  obtained  at  the  time 
of  injury,  down  growing  neuraxes  may  or  may  not  reach  the  distal  segment, 
depending  on  the  character  of  the  intervening  scar  and  the  distance  of  separa- 
tion. In  case  the  divided  nerve  ends,  owing  to  loss  of  nerve  substance,  are 
separated  to  such  extent  that  they  can  not  be  brought  to  approximation  and 
maintained  so  by  suture  either  at  a  primary  or  secondary  operation,  a  method 
of  bridging  the  gap  so  as  to  give  a  conduit  for  the  down  growing  central 
neuraxes  is  deserving  of  consideration.     The  question  of  bridging  defects  in 


68  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

injured  nerves  has  engaged  the  attention  of  surgeons  and  experimentors  almost 
since  the  beginning  of  our  knowledge  of  nerve  de-  and  regeneration,  and  an 
extensive  literature  dealing  with  the  question  has  developed.  Certain  phases 
of  the  experimental  work  bearing  on  the  problem  of  bridging  nerve  defects 
may  here  be  considered,  since  the  results  attained  throw  light  on  the  process 
of  nerve  repair  and  contirm  in  a  very  substantial  way  the  down  growth  or 
monogenetic  view  of  nerve  regeneration. 

Of  the  several  methods  of  bridging  nerve  defects  which  have  been  tried 
either  experimentally  or  clinically,  that  of  nerve  transplantation  has  received 
the  most  extensive  consideration,  and  deservedly  so  since  in  experimental 
work  it  has  given  the  most  satisfactory  results. 

The  first  systematic  histological  study  of  the  degeneration  and  regenera- 
tion of  a  nerve  transplant  was  made  by  Huber  (1895).  He  then  reported  on  an 
experimental  study  of  the  repair  of  peripheral  nerves  after  loss  of  nerve  sub- 
stance. This  study  included  twenty-six  experiments  of  heterotransplantation, 
in  which  the  sciatic  of  a  cat  was  transplanted  to  a  resected  ulnar  of  a  dog, 
the  several  experiments  varying  in  length  from  2  days  to  182  days.  A  careful 
histological  study  of  the  operated  nerve,  including  the  transplant,  was  made. 
The  morphological  changes,  noted  in  the  nerve  libers  of  the  heterotransplant, 
were  reported  as  not  differing  materially  from  those  noted  in  a  peripheral  nerve 
during  degeneration.  The  degenerated  fibers  of  the  nerve  transplant  were 
found  to  contain  nucleated  bands  of  protoplasm;  however,  the  nuclei  were  found 
to  be  much  less  numerous  than  in  the  syncytial  nucleated  bands  found  in  the 
degenerated  peripheral  nerve.  Regeneration  was  found  to  begin  in  the  central 
stump  of  the  resected  nerve  and  to  proceed  centrifugally.  The  process  of 
regeneration  was  studied  by  means  of  the  Stroebe  method  of  neuraxis  differ- 
entiation. Neuraxes  derived  from  the  central  stump  could  be  traced  through 
the  central  wound,  into  the  transplant,  and  through  the  distal  wound  into  the 
distal  segment  of  resected  nerve.  Both  in  sections  and  in  teased  preparations 
could  newly  formed  neuraxes  be  found  in  the  old  sheaths  of  the  fibers  of  the 
heterotransplant.  Ballance  and  Stewart  (1901)  reported  on  observations  on 
auto-  and  heteronerve  transplantation.  Degeneration  was  said  to  occur  in  the 
graft  as  in  the  distal  segment  of  a  divided  nerve.  Neuroblasts,  from  which 
embryonical  sheaths  are  said  to  have  been  derived,  were  found  to  have  invaded 
the  graft  from  both  the  distal  and  proximal  segments.  Merzbacher  (1905)  was 
the  first  to  call  attention  to  the  fact  that  discrimination  should  be  made  between 
auto-,  homo-,  and  heteronerve  transplants.     According  to  the  experimental 


NERVE  DEGENERATION  AND  REGENERATION  69 

work  of  this  observer  auto-,  and  homonerve  transplants  survive  in  the  host 
and  would  thus  degenerate  as  does  the  peripheral  segment  of  a  divided  nerve, 
while  a  heteronerve  transplant  becomes  necrotic.  These  results  were  in  the 
main  confirmed  by  the  observations  of  Segale  (1905).  As  a  result  of  experi- 
mental observations  Verga  (1910)  and  Maccabruni  (1911)  reached  the  conclu- 
sion that  the  results  were  the  same  whether  homo-  or  heteronerve  transplants 
were  used.  Ingebrigsten  (1915),  who  has  given  special  consideration  to  the 
behavior  of  the  nerve  fibers  in  nerve  transplants,  expresses  himself  as  follows: 

"In  autoplastic  transplanted  nerves  a  degenerative  process  occurs  which 
resembles  the  ordinary  Wallerian  degeneration,  but  appears  a  little  more 
slowly  than  the  latter.  The  cells  of  Schwann  are  in  a  condition  of  survival 
and  are  capable  of  multiplication  after  the  transplantation.  In  homoplastic 
transplanted  nerves  I  have  found  a  degenerative  process  resembling  a  Wallerian 
degeneration,  somewhat  delayed.  The  cells  of  Schwann  multiply,  and  for  a 
time  at  least  are  in  a  condition  of  survival.  After  twelve  to  fourteen  days  an 
abundant  and  increasing  immigration  of  lymphocytes  is  observed,  and  from  the 
eighteenth  day  cells  of  Schwann  develop  a  necrobiotic  appearance.  In 
heteroplastic  transplanted  nerves,  numerous  myelin  ovoids  are  formed 
during  the  first  four  to  five  days,  but  there  is  no  proliferation  of  the  cells  of 
Schwann  and  no  Wallerian  degeneration  is  seen.  The  graft  becomes  necrotic 
within  about  two  weeks."  Throughout  this  work  stress  is  laid  on  the  behavior 
of  the  sheath  cells,  the  cells  of  Schwann;  their  survival  and  multiplication. 
He  states:  "The  solution  of  this  point,  which  is  the  only  reliable  sign  of  the 
survival  of  the  transplanted  piece,  gives  the  key  to  the  problem  and  will  influence 
the  procedure  of  surgeons  in  case  of  nerve  defects."  As  the  result  of  more 
recent  observations  by  Ingebrigsten  (1918)  in  which  use  was  made  of  stored  nerve 
transplants,  the  conclusion  was  reached  that  the  cells  of  Schwann  of  auto-  and 
homotransplants  are  without  any  biological  significance  for  the  regeneration 
of  neurofibrils,  which  grow  into  the  transplant  from  the  central  stump  whether 
the  transplant  is  living  or  dead. 

An  extensive  series  of  experiments  on  nerve  transplantation,  carried  out  in 

conjunction  with  the  Division  of  Head  Surgery  of  the  Office  of  the  Surgeon 

General,^  has  been  reported  upon  in  a  brief  preliminary  note  by  Huber  (1919). 

'  This  experimental  work  was  carried  out  in  tlie  Department  of  Anatomy,  University  of  Miclii- 
gan,  under  the  direction  of  G.  Carl  Huber;  Lieut.  Col.  Dean  D.  Lewis,  Blajor  J.  F.  Corbett,  Major 
Byron  Stookey  and  Major  T.  Roberg  in  succession  received  assignment  to  this  laboratory  with  a 
view  of  assisting  in  an  experimental  study  of  nerve  repair.  To  their  initiative,  untiring  and  hearty 
co-operation,  the  progress  of  the  work  is  greatly  indebted. 

G.  Carl  HtrsER. 


70  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

This  series  covers  somewhat  over  150  experimental  operations  on  nerve  trans- 
plantation made  on  the  sciatic  nerve  of  dogs  and  rabbits,  and  includes  experi- 
mental observations  on  auto-,  homo-,  and  heterogeneous  nerve  transplants, 
either  used  as  fresh  tissue,  immediately  after  removal,  or  as  nerve  transplants 
stored  in  sterile  media  for  varying  periods  of  time.  The  primary  object  of  this 
extensive  series  of  experiments  was  to  determine  the  virtue  of  a  nerve  bridge 
as  a  means  of  conducting  down  growing  central  neuraxes  from  the  proximal  to 
the  distal  stump,  with  a  view  of  ascertaining  the  value  of  the  nerve  transplant 
in  practical  surgery.  Under  the  conditions  of  work,  the  biology  of  the  nerve 
transplant  was  of  secondary  consideration.  In  the  histological  study  of  the 
operated  nerve,  at  the  conclusion  of  the  respective  experiments,  special  con- 
sideration was  thus  given  to  neuraxis  differentiation.  In  nearly  all  of  the 
experiments  use  was  made  of  the  Ranson  pyridine-silver  method  of  neuraxis 
differentiation.  This  method  admits  of  block  staining  and  this  faciHtates  the 
cutting  of  serial  sections,  so  essential  to  the  determination  of  neuraxis  down 
growth  and  development.  The  nuclei  of  the  sheath  cells  and  of  the  connective 
tissue  are  by  this  method  not  clearly  brought  to  view.  The  myelin  sheaths 
are  stained  a  bright  yellow,  and  the  fragmentation  of  the  myelin  is  not  always 
clearly  followed.  Therefore,  the  histological  preparations  obtained  from  this 
series  do  not  permit  of  drawing  lanal  conclusive  observations  as  to  the  behavior 
of  the  nerve  libers  of  the  transplants,  especially  as  concerns  their  degeneration, 
while  definite  conclusions  may  be  drawn  relative  to  the  down  growing  neuraxes, 
derived  from  the  proximal  segment. 

So  far  as  may  be  determined  on  gross  inspection  and  in  histological  pre- 
parations, the  character  of  the  transplant  does  not  materially  influence  the 
fibrous  union  of  the  respective  ends  of  the  transplanted  nerve  segment  and  the 
resected  nerve  ends.  The  fibroblastic  reaction  appears  to  be  essentially  the 
same  whether  auto-,  homo-  or  heterogeneous  nerve  segment  is  used,  the  general 
conditions  of  the  experiment  remaining  otherwise  the  same.  The  same  may 
be  said  of  the  reaction  of  the  surrounding  connective  tissue  to  the  transplant. 
So  far  as  may  be  determined  in  material  stained  after  the  pyridine  silver  method, 
the  manner  of  the  degeneration  of  the  nerve  fibers  of  the  nerve  transplant  is 
not  identical  with  that  of  the  peripheral  segment  of  a  degenerating  nerve.  A 
fragmentation  of  the  myelin  sheaths  and  the  neuraxes  of  the  nerve  fibers  of 
the  nerve  transplant  is  observed,  which  more  especially  in  the  earlier  stages 
resembles  Wallerian  degeneration,  and  may  take  place  more  rapidly,  and  again 
less  rapidly,  than  in  the  peripheral  segment  of  the  nerve.     The  participation 


NERVE  DEGENERATION  AND  REGENERATION  7 1 

of  the  sheath  cells  in  the  nerve  fibers  of  the  transplant  during  the  fragmenta- 
tion and  removal  of  the  myelin  is  difficult  to  ascertain  in  silver  stained  prepa- 
rations, since  they  are  generally  only  very  lightly  stained  and  not  clearly 
differentiated.  Therefore,  we  are  not  in  a  position  to  add  to  the  observations 
of  Ingebrigtsen  as  regards  the  sheath  cells  of  the  transplant.  The  considera- 
tion of  the  behavior  of  the  sheath  cells  of  the  nerve  fibers  in  the  transplant 
assumes  less  importance  when  regarded  from  the  viewpoint  of  practical  surgery, 
since  it  has  been  experimentally  demonstrated  that  homo-nerve  transplants 
stored  in  sterile  media  deserve  serious  consideration  in  bridging  nerve  defects. 
Following  the  suggestion  of  Dujarier  and  Francois  (1918),  homo-nerve  trans- 
plants were  stored  in  sterile  petrolatum  and  liquid  petrolatum,  kept  at  3°C. 
for  intervals  varying  from  8  to  40  days,  and  then  in  48  experiments  used  to 
bridge  nerve  defects,  and  in  18  experiments,  following  the  suggestion  of  Nage- 
otte  (1918),  homo-nerve  transplants,  stored  in  50%  alcohol,  for  intervals  vary- 
ing from  7  to  25  days,  were  similarly  used.  In  these  series  of  experiments  the 
nerve  segments  thus  stored  do  not  retain  a  latent  viability.  The  sheath  cells 
show  no  evidence  of  proliferation  and  appear  not  to  have  biological  significance. 
In  the  nerve  fibers  of  the  nerve  segments  thus  stored  and  used  as  transplants, 
the  fragmentation  of  the  myelin  and  neuraxes  takes  place  relatively  slowly, 
proceeding  less  rapidly  than  in  the  peripheral  segment.  The  removal  of  the 
debris,  derived  from  the  fragmentation  of  the  myelin  sheaths  and  neuraxes  of 
the  transplanted  fibers,  appears  to  proceed  less  rapidly  in  the  nerve  transplant 
than  in  the  peripheral  segment  in  the  resected  nerve.  Many  of  the  fibers  for 
periods  of  weeks  show  distended  neurolemma  sheaths,  filled  with  globules  of 
myelin.  Especially  is  this  true  in  hetero-nerve  transplantation.  The  forma- 
tion of  the  characteristic  nucleated  syncytial  protoplasmic  bands,  the  end  result 
of  the  degeneration  of  periphreal  nerve  fibers,  has  not  been  clearly  demonstrated 
in  the  degenerating  fibers  of  the  nerve  transplant,  irrespective  as  to  whether 
these  be  of  auto-,  homo-  or  heterogeneous  nerve  tissue.  The  neurolemma 
sheaths  of  the  transplanted  nerve  fibers  are  thought  to  persist,  after  the  breaking 
down  of  the  myelin  sheaths  and  neuraxes,  as  in  the  peripheral  segment  of  the 
nerve,  even  when  heteroplastic  tissue  is  used.  The  perineural  and  epineural 
sheaths  of  the  nerve  transplant  are  not  materially  altered  by  transplantation, 
except  that  they  may  show  leucocyte  invasion,  irrespective  of  the  character  of 
the  nerve  transplant. 

Regeneration  of  the  distal  segment  of  a  resected  nerve,  with  gap  bridged  by 
a  nerve  transplant,  is  by  down  growth  of  neuraxes  derived  from  the  central 


72 


SURGICAL   AND    MECHANICAL   TREATMENT   OF   PERIPHERAL  NERVES 


stump,  through  the  transplant  to  the  distal  segment.  This  has  been  clearly 
demonstrated  in  pyridine  silver  preparations  obtained  from  the  long  series  of 
experimental  operations  above  referred  to.  In  the  course  of  this  experimental 
work  there  was  devised  an  operation  which  we  designated  as  "cable  autonerve 
transplant,"  in  which  a  number  of  segments  of  a  smaller  nerve  were  used  to  bridge 
a  defect  in  a  larger  nerve.     In  the  experiments  in  question  four  segments  of  the 


Fig.  23. — Microphotograph  of  nerve  transplant.  Longitudinal  section  at  point  of  central 
suture  26  days  after  suture.  Ranson  pyridine  silver  stain.  Neuraxes  are  seen  entering  transplant 
after  passing  through  line  of  suture.     Central  end  to  left. 

cutaneous  radial  branches  of  the  ulnar  of  a  dog  were  used  to  bridge  a  defect  in 
the  sciatic  nerve  of  the  same  dog.  Witliin  the  first  week  after  the  operation  the 
several  segments  of  the  nerve  transplant  became  surrounded  by  newly  formed 
connective  tissue,  binding  the  several  segments  together  in  one  common  trunk  so 
as  to  form  a  common  epineural  sheath  in  which  the  funicular  arrangement  of 
the  several  transplanted  segmentsis  fully  maintained.  In  an  experiment  termin- 
ated the  eleventh  day,  down  growing  neuraxes  of  the  proximal  end  are  found  in 


NERVE  DEGENERATION  AND  REGENERATION 


73 


the  connective  tissue  uniting  the  transplanted  nerve  segments  to  the  proximal 
end,  but  none  are  found  in  the  nerve  transplant.  In  a  similar  experiment  termi- 
nated the  twenty-sixth  day  after  the  operation,  down  growing  neuraxes  in 
appreciable  numbers  have  penetrated  the  central  wound  and  are  found  in 
all  of  the  funicuU  of  each  of  the  four  transplanted  nerve  segments.     Practically 


Fig.  24. — Jlicrophotograph  of  cable  transplant,  26  days  after  suture.  Cross  se  ction 
through  middle  of  graft  transplant.  Ranson  pyridine  silver  stain.  Note  that  the  funiculi  are  filled 
with  downgrowing  neuraxes. 

no  down  growing  neuraxes  are  found  in  the  connective  tissue  surrounding  the 
transplanted  nerve  segments.  The  down  growing  neuraxes  found  within  the 
funiculi  of  the  transplanted  nerve  segments  are  found  mainly  within  the  neuro- 
lemma sheaths  of  the  transplanted  nerve  fibers.  (See  Figs.  23  and  24.)  They 
have  not  as  yet  reached  the  distal  wound,  a  distance  of  2  cm.,  and  no  new  neuraxes 
are  found  in  the  distal  segment  of  the  sciatic.  In  experiments  terminated  approxi- 
mately three  months  after  the  operation,  one  a  primary  operation  and  the  other  a 
secondary  operation,  new  neuraxes  were  found  to  extend  from  the  central  stump, 


74  SURGICAL   AND    MECHANICAL    TREATMENT   OF   PERIPHERAL   NERVES 

through  the  four  transplanted  segments,  into  the  distal  sciatic  and  in  this  to  the 
muscular  branches  found  within  the  calf  muscles,  while  the  more  distal  sciatic 
was  as  yet  completely  degenerated.  In  similar  experiments  terminated  approxi- 
mately one  year  after  operation,  down  growing  neuraxes  had  extended  distally 
so  as  to  include  the  smaller  foot  muscles.  (See  Fig.  25.)  In  fresh  homoplastic 
nerve  transplantation,  a  fresh  segment  of  the  sciatic  of  one  rabbit  transplanted  to 
the  resected  sciatic  of  another  rabbit,  down  growth  of  central  neuraxes  through 
a  transplant  of  i  cm.  length  was  noted  in  an  experiment  terminated  33  days 
after  operation,  and  for  a  distance  of  about  2  cm.  into  the  distal  segment  of  the 
sciatic  in  a  similar  experiment  terminated  two  months  after  operation.  The 
down  growing  neuraxes  were  found  both  within  the  neurolemma  sheaths  of  the 
transplanted  nerve  fibers  and  also  between  the  iibers.  In  an  extended  series  of 
experimental  observations  in  which  stored  homoplastic  nerve  transplants  were 
used,  down  growth  of  neuraxes  through  nerve  segments  stored  in  sterile  petrola- 
tum, Kquid  petrolatum  and  50%  alcohol  was  demonstrated.  Homonerve 
transplants  of  nerve  segments  stored  in  liquid  petrolatum  readily  formed  con- 
nective tissue  union  with  the  resected  nerve  ends.  In  such  an  experiment  ter- 
minated at  the  eighth  day,  down  growing  neuraxes  were  found  in  the  connective 
tissue  of  the  central  wound.  In  a  similar  experiment  terminated  the  twenty- 
third  day,  down  growing  neuraxes  derived  from  the  central  stump  may  be  traced 
through  the  central  wound  in  the  proximal  end  of  the  nerve  transplant  in  which 
they  are  found  in  large  numbers.  In  many  of  the  old  neurolemma  sheaths  of  the 
nerve  fibers  of  the  transplant  more  than  one  down  growing  neuraxis  is  to  be  found. 
The  down  growing  neura.xes  are  found  to  be  progressively  less  numerous 
as  the  distal  portion  of  the  nerve  transplant  is  reached,  and  do  not  extend  to  the 
distal  wound,  a  distance  of  3  cm.  The  distal  segment  of  the  nerve  was  completely 
degenerated;  no  neuraxes  could  be  differentiated  in  it.  In  experiments  termi- 
nated more  than  three  months  after  the  operation  in  which  homo-nerve  trans- 
plants of  3  cm.  length,  stored  in  liquid  petrolatum  were  used,  satisfactory, 
neurotization  of  the  distal  segment  of  the  sciatic  was  obtained.  The  down 
growing  neuraxes  could  be  traced  from  the  distal  end  of  the  proximal  segment, 
through  the  transplant  and  distal  wound  into  the  distal  segment  of  the  nerve. 
In  the  longer  time  experiments  regeneration  of  the  motor  endings  in  the  calf 
muscles  was  observed.  The  experiments  with  homonerve  transplants,  with  the 
nerve  segments  stored  in  50%  alcohol,  are  of  special  interest  since  it  cannot  be 
questioned  that  one  is  dealing  here  with  dead  nerve  tissue,  and  a  survival  of 
sheath  cells,  in  nerve  segments  stored  several  weeks  in  50%  alcohol,  cannot  be 


Fig.  25  — Section  through  the  calf  muscles  of  a  dog  103  days  after  cable  transplant  to  bridge 
defect  in  sciatic  nerve.  Ranson  pyridine  silver  stain.  Two  centimeters  excised  from  the  sciatic 
nerve  in  the  thigh  and  defect  bridged  by  four  autotransplants.  Section  shows  regenerating  nerve 
fibers  between  the  muscle  bundles. 


NERVE  DEGENERATION  AND  REGENERATION  75 

assumed.  In  these  experiments  the  sciatics  of  rabbits  were  placed  in  50% 
alcohol  in  wh'ch  they  were  kept  until  desired.  At  the  time  of  an  experiment  the 
nerve  segment  to  be  used  was  taken  from  the  alcohol  and  placed  in  warmed, 
sterile  saline  solution  for  15-30  minutes  and  then  used  as  transplant.  Such 
a  nerve  transplant  makes  connective  tissue  union  with  the  resected  nerve  ends 
very  readily  and  there  is  noted  very  httle  reaction  in  the  connective  tissue 
surrounding  the  nerve  transplant.  In  such  an  experiment  terminated  23  days 
after  the  operation,  new  neuraxes  could  be  traced  from  the  central  stump 
through  the  central  wound  into  the  central  end  of  the  nerve  transplant.  In  a 
similar  experiment  terminated  42  days  after  operation,  very  few  new  neuraxes 
could  be  traced  through  the  transplant  into  the  proximal  end  of  the  distal  seg- 
ment. In  this  experiment  the  new  neuraxes  were  quite  abundant  in  the  central 
end  of  the  transplant.  In  eight  experiments  in  which  alcohol-stored  homo- 
nerve  transplants  were  used,  the  period  of  observation  was  more  than  three 
months,  and  in  each  of  these  neurotization  of  the  distal  segment  through  the 
transplant  was  attained.  The  down  growing  neuraxes,  derived  from  the 
central  stump,  in  these  experiments  were  found  in  part  in  the  old  neurolemma 
sheaths  of  the  nerve  libers  of  the  transplant,  as  well  as  in  the  connective  tissue 
between  the  fibers.  Within  the  transplant,  the  down  growing  neuraxes  present 
a  quite  regular,  longitudinal  arrangement,  quite  different  from  that  found  in  the 
central  and  distal  wounds,  in  which  they  have  a  very  irregular  course. 

In  the  experiments  on  hetero  nerve  transplants,  segments  of  the  sciatic 
nerve  of  guinea-pigs  were  transplanted  to  the  sciatic  of  rabbits.  The  gross 
appearance  of  a  hetero  nerve  transplant,  seen  two  to  three  weeks  after 
operation,  is  quite  similar  to  that  of  an  auto-  or  homoplastic  nerve  trans- 
plant similarly  observed.  Fibrous  tissue  union  with  the  two  ends  of  the 
resected  nerve  is  easily  attained.  In  pyridine  silver  preparations  the  remains 
of  the  neuraxes  of  the  nerve  fibers  of  the  heterotransplant  may  be  seen  three  to 
four  weeks  after  the  operation,  especially  in  the  portions  of  the  transplant 
bordering  the  proximal  and  distal  wounds.  These  neuraxes  remains  are  of 
irregular  contour  and,  though  they  may  stain  differentially,  are  readily  dis- 
tinguished from  the  fine,  down  growing  neuraxes  derived  from  the  central 
stump.  From  a  study  of  pyridine  silver  preparations,  it  is  quite  clear  that  down 
growing  neuraxes  derived  from  the  central  stump  may  enter  a  heteroplastic 
nerve  transplant  and  pass  through  it  to  the  distal  segment.  The  number  of 
down  growing  neuraxes  that  are  observed  to  pass  through  a  heteronerve  trans- 
plant, however,  is  not  nearly  so  great  as  that  observed  in  auto-  and  homoplastic 


76  SURGICAL   AND    MECHANICAL    TREATMENT    OF    PERIPHERAL   NERVES 

nerve  transplants.  In  heteronerve  transplants  many  down  growing  neuraxes 
were  found  in  the  connective  sheaths  of  the  transplant  and  in  the  surrounding 
connective  tissue,  and  thus  reach  the  distal  segment  not  so  much  through  as  on 
the  transplant.  Return  of  motor  function  was  attained  in  a  number  of  long- 
time experiments  in  which  heteroplastic  transplants  were  used.  The  results, 
however,  were  not  nearly  so  satisfactory  as  when  auto-  or  homoplastic  nerve 
transplants  were  used.  The  experimental  observations  on  nerve  transplants 
give  very  convincing  evidence  in  support  of  the  down  growth  or  the  mono- 
genetic  theory  of  nerve  regeneration.  Especially  in  the  experiments  of  auto- 
and  homogeneous  nerve  transplants  may  it  be  observed  that  the  down  growing 
neuraxes,  developed  from  the  distal  end  of  the  proximal  stump,  penetrate  the 
organizing  connective  tissue  of  the  central  wound  very  much  as  in  primary  or 
secondary  nerve  suture.  These  down  growing  neuraxes  reach  the  central  end 
of  the  transplanted  nerve  segment,  whether  auto-  or  homoplastic,  or  homoplas- 
tic stored  in  petrolatum  or  50%  alcohol,  from  the  tenth  to  the  fifteenth  day 
after  operation,  depending  on  the  degree  of  successful  approximation  of  nerve 
ends.  In  the  transplant,  the  down  growing  neuraxes  may  be  traced  progres- 
sively through  the  transplant  to  the  region  of  the  distal  wound,  at  a  rate 
which  is  on  the  whole  very  similar  to  that  pertaining  in  regeneration  of  the 
distal  segment  of  a  divided  nerve.  Within  the  transplant  many  of  the  down 
growing  neuraxes  are  found  within  what  are  regarded  as  neurolemma  sheaths  of 
the  transplanted  nerve  fibers;  even  though  these  do  not  contain  distinct,  nucle- 
ated syncytial  protoplasmic  bands.  Other  neuraxes  appear  to  be  between  the 
nerve  fibers  of  the  transplant.  That  the  sheaths  or  neurolemma  cells  of  the 
transplant  are  not  of  special  or  specific  significance  to  the  down  growing 
neuraxes  is  shown  by  the  experiment  of  stored  homonerve  transplants.  The 
supposition  is  permissible  that  in  nerve  segments  stored  in  petrolatum  and  liquid 
petrolatum  at  a  temperature  of  3°C.  some  degree  of  viability  in  the  neurolemma 
and  connective  tissue  cells  is  retained,  even  though  there  is  no  satisfactory 
evidence  of  the  proliferation  of  the  sheath  or  neurolemma  cells  of  the  nerve 
fibers  of  the  stored  nerve  transplant.  In  the  case  of  the  transplant  of  the  50% 
alcohol  stored  nerve,  it  cannot  be  supposed  that  viability  is  retained  in  any 
of  the  cells  or  tissue  elements  of  the  transplanted  nerve  fibers.  Their  participa- 
tion in  any  way  in  the  down  growth  of  the  central  neuraxis  through  the  trans- 
plant, therefore,  may  be  excluded.  In  the  transplant  the  down  growing 
neuraxes  have  a  regular  longitudinal  arrangement  much  as  that  observed  in  a 
regenerating  distal  segment  of  an  injured  peripheral  nerve.     In  pyridine  silver 


NERVE  DEGENERATION  AND  REGENERATION  77 

preparations  ot  successive  stages,  the  down  growing  neuraxes  may  be  traced  to 
the  distal  part  of  the  nerve  transplant  at  a  time  when  neither  in  cross  nor  longi- 
tudinal sections  any  neuraxes  may  be  observed  in  the  distal  segment  of  the 
resected  nerve,  all  the  nerve  libers  presenting  an  advanced  stage  of  degenera- 
tion. After  reaching  the  distal  portion  of  the  nerve  transplant  the  new  neuraxes 
may  in  longer  time  experiments  be  traced  into  the  distal  wound,  which,  consist- 
ing of  more  fully  developed  connective  tissue  than  that  of  the  central  wound 
at  the  time  of  its  penetration  by  down  growing  neuraxes,  offers  proportionately 
greater  resistance  to  the  down  growing  neuraxes.  In  the  region  of  the  distal 
wound  the  neuraxes  present  show  a  very  irregular  course,  taking  circuitous 
paths,  usually  as  single  libers  or  small  bundles  of  fibers,  between  the  connective 
tissue  bundles.  From  the  distal  wound  the  neuraxes  may  be  traced  to  degen- 
erated nerve  in  the  proximal  end  of  the  distal  segment.  In  none  of  the  experi- 
ments on  nerve  transplantation  were  new  neuraxes  found  in  the  degenerated 
hbers  of  the  distal  segment  unless  they  could  in  cross  and  longitudinal  sections, 
stained  after  the  pyridine  silver  method,  be  traced  from  the  central  stump 
through  or  on  the  nerve  transplant  to  the  distal  segment. 

A  further  series  of  experiments  were  considered  as  giving  confirmatory 
evidence  in  support  of  the  down  growth  or  monogenetic  theory  of  nerve 
regeneration.  In  certain  experiments  in  which  the  ulnar  nerve  of  dogs  was 
resected  to  the  extent  of  4  to  5  cm.,  the  resected  ends  of  the  nerve  were 
inserted  into  the  lumen  of  formalized  arterial  tubes,  stored  in  95  %  alcohol, 
and  before  use  placed  for  about  30  minutes  in  warmed,  sterile  sahne  solution. 
The  resected  nerve  ends  were  retained  within  the  ends  of  the  arterial  tubes  by 
means  of  tine  silk  sutures.  Arterial  tubes  thus  prepared  are  retained  without 
absorption  for  a  period  of  at  least  five  months.  Their  presence  in  the  tissues 
does  not  especially  incite  connective  tissue  formation.  There  is  practically 
no  penetration  of  connective  tissue  through  the  wall  of  the  tube.  While  the 
arterial  tube  is  found  collapsed,  sufficient  lumen  is  retained  to  admit  of  down 
growth  of  neuraxes  derived  from  the  central  stump.  In  four  of  the  experiments 
kept  longer  than  four  months  down  growing  neuraxes  derived  from  the  central 
stump  had  passed  through  the  lumen  of  the  artery,  in  one  experiment  a  distance 
of  approximately  4  cm.,  and  reached  the  distal  segment  of  the  nerve,  in  which 
beginning  regeneration  was  noted.  In  these  experiments  no  neuraxes  were 
found  in  the  distal  stump  of  the  divided  nerve,  unless  they  could  be  traced 
from  the  proximal  end  of  the  nerve  through  the  lumen  of  the  arterial  tube  to 
the  distal  segment. 


yS  SURGICAL    AXD    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

REFERENCES 

Arnemann:  Versuche  uber  die  Regeneration  an  lebenden  Tieren,  Gijttingen,  1787. 
Balfour:  On  the  development  of  the  spinal  nerves  in  elasmobranch  fishes.     Philos,  Trans., 

1875- 
Ballance  and  Stewart:  The  Healing  of  Nerves,  Macmillan  and  Co.,  1901. 
Bethe:  Allgemeine  Anatomie  und  Physiologie  des  Nervensystems,  1903. 
Boeke:  Studien   zur    Nervenregeneration.     No.    i.     Die   Regeneration   der    motorischen 

Nervenelemente,  etc.,  Verhand.  der  Kon.  Akad.  van  Wet.,  Amsterdam,  1916. 
Boeke:  Studien    zur    Nervenregeneration,   No.    2.     Die  Regeneration  nach  Vereinigung 

unglichartiger  Nervenstiicke,  etc.,  Verhand.  der.  Kon.  Akad.  von  Wet.,  Amsterdam,  1917. 
Bunger:  Uber  die  Degenerations-  und  Regenerationsvorgange  am  Nerven  nach  Verlet, 

zungen,  Ziegler's  Beitr.  z.  path.  Anat.  ,v.  10:  1891. 
Cajal:  Nervenregeneration,  Barth,  Leipzig,  1908. 
Cruikshank:  Experiments  on  the  nerves,  particularly  on  their  reproduction,  etc.,  Philosoph. 

Transactions,  1795. 
Dohrn:  Die  Schwannchen   Kerne,  ihre  Herkunft  und  Bedeutung,  Mitteil.  d.  Zool.  Stat. 

Napels,  v.  15:  1901. 
Doinikow:  Beitrage  zur  Histologic  und  Histopathologic  der  peripheren   Nerven.  Nissl- 

Alzheimer,  Histologische  und  Histopathologische  Arbeiten,  v.  4:  1911. 
Dujarier  et  Francois:  Sur  vingt  cas  de  griflfe  homoplastique  dans  les  sections  nerveuses 

Bull,  et  mem.  Soc.  de  Chir.  de  Paris,  v.  44:  1918. 
Ditstin:  Les  lesions  posttraumatiques  des  nerfs.  Ambulance  de  I'ocean,  Vase.  2:  1917. 
Galeoti  and  Levi:  Uber  die  Neubildung  des  nervosen  Elemente,  etc.,  Ziegler's  Beitr.  z. 

Path.  Anat.  v.,  17:  1895. 
Haighton:  An  experimental  inquiry  concerning  the  reproduction  of  nerves,  Philosoph. 

Transactions,  1795. 
Harrison:  Further  experiments   on  the  development  of  peripheral  nerves,  .^mer.  Jour. 

Anat.,  V.  5:  1906. 
Harrison:  Observations    of  the  living  developing  nerve  fibers,  Proceed.  Soc.  Exp.  Biol. 

and,  Med.,  v.  4:  1907. 
Held:    Die  Entwicklung  des  Nervengewebes  bei  den  Wirbeltieren,  1909. 
His:  Histogenese  und  Zusammenhang  der  Nervenelemente,   Arch.   f.   Anat.   und  Phys. 

Suppl.,  i8go. 
Howell  and  Hitber:  A  physiological,  histological  and  clinical  study  of  the  degeneration 

and  regeneration  in  the  peripheral  nerve  fibers.  Jour.  Phys.,  v.  13:  1892. 
Huber:  L^ber  das  Verhalten  der  Kerne  der  Schwann'schen  Scheide  bei  Nervendegenera- 

tionen.  Arch.  f.  Mik.  Anat.,  Bd.  40,  1892. 
Huber:  A  study  of  the  operative  treatment  for  loss  of  nerve  substance  in  peripheral  nerves. 

Jour.  IMorph.,  v.  2:  1S95. 
Huber:  Observations  on  the  degeneration  and  regeneration  of  motor  and  sensory  nerve 

endings  in  voluntary  muscle,  Amer.  Jour.  Phys.,  v.  3:  1900. 
Huber:  Transplantation  of  peripheral  nerves.  Arch,  of  Neurol,  and  Psych.,  v.  2:  1919. 
Ingebrigtsen:  Am  Nerventransplantation,  Christiania,  1918. 


NERVE  DEGENERATION  AND  REGENERATION  79 

Ingebrigtsen:  a  contribution  to  the  biology  of  peripheral  nerves  in  transplantation,  Jour. 

Exp.  Med.,  V.  22;  1915. 
Kennedy:  On  the  regeneration  of  nerves,  Philosoph,  Transactions,  v.  188:  1897. 
Kirk   and  Lewis:   Regeneration  in  peripheral  nerves,  Johns  Hopkins  Hospital  Bull.,  v. 

28:  1917. 
Krassin:    Uber    die   Regeneration    des   peripheren   Nerven   nach   Verletzung,  Internal. 

Monatsch.  f.  Anat.  v.  25,  1908. 
Langley  and  Antderson:  An  autogenetic  regeneration  in  the  nerves  of  limbs,  Jour.  Phys., 

v.  31:  1904. 
LuGARO:  Zur   Frage   der   autogenen   Regeneration   des  Nervenfasern,   Neurol.    Centralbl. 

v.  24:  1905. 
Maccabruni:  Des  Degenerations-prozess  der  Nerven  bei  homoplastischen  and  heteroplas- 

tischen  Propfungen,  Folia  Neuro-Biologica,  v.  5;  1911. 
Merzbacher:  Zur   Biologie   der   Nervendegeneration   (Ergebnisse   von  Transplantations- 

versuchen)  Neurolog.  Centralbl.,  v.  24:  1905. 
MoNCKEBERG  and  Bethe:  Die  Degeneration  des  markhaltigen  Nervenfasern  der  Weibel- 

tiere,  etc.,  Arch.  f.  Mik.  Anat.,  v.  54,  1899. 
Nageotte:  Etude  experimentale  sur  les  inconvenients  de  la  suture  nerveuse  directe  et  sur 

un  precede  de  suture  indireclc,  permettant  de  les  eviter.  Bull,  et  mem.  de  la  Soc.  de 

Chir.  de  Paris,  v.  44:  1918. 
Nasse:  Uber  die    Veranderung    der  Nervenfasern  nach  ihrer  Durchschneidung,  Miiller's 

Archiv.,  1839. 
Perroncito:  Die  Regeneration  des  Nerven,  Ziegler's  Beit.  z.  Path.  Anat.,  v.  42;  1907. 
Philipeax  et  Vulpian:  Journal  de  la  Physiol.,  v.  3:  i860. 
Poscharissky:  Uber  die   histologischen   Vorgange   an   den   peripherschen  Nerven   nach 

Kontinuitiitslrennung,  Ziegler's  Beit.  f.  Path.  ,\nat.,  v.  41:  1907. 
Ranson:  Degeneration  and  Regeneration  of  Nerve  Fibers,  Jour.  Comp.  Neurol.,  v.  22:1912. 
Ranvier:  Lecons  sur  I'histologie  du  systeme  nerveux,  1878. 
Segale:  La  Riforma  medica,  1905. 
Streeter:  Development  of  the  Nervous  System.     Keibel  and  Mall.     Manual  of  Human 

Embr>'ology,  v.  2:  1912. 
Stroebe:  E.xperimentalle  L^ntersuchungen  iiber  Degeneration  und  Regeneration  peripherer 

Nerven  nach  Verletzungen,  Ziegler's  Beit.  z.  path.  .\nat.,  v.  13:  1893. 
Tello:  Degeneration  et  regeneration  des  plaques  mot  rices  apres  la  section  des  nerfs,  Traba- 

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Archiv,  1852,. 
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V.  23:  1898. 


CHAPTER  III 
METHODS  OF  NERVE  REPAIR 

During  the  development  of  peripheral  nerve  surgery  numerous  methods  of 
nerve  repair  have  been  evolved,  both  clinically  and  experimentally.  Some  are 
based  on  a  correct  conception  of  the  histological  processes  of  nerve  regeneration, 
and  others  in  ignorance  of  such  processes,  have  applied  to  nerves  methods 
suited  to  tendons,  due  to  the  more  or  less  gross  resemblance  of  the  two. 

Standardization  of  Terms. — Before  discussing  the  value  of  the  various 
methods  of  nerve  repair,  it  might  be  well  to  discuss  the  terms  that  common 
usage  has  applied  to  them.  Unfortunately,  there  has  been  considerable 
variance  and  lack  of  standard  terms  both  in  this  country  and  abroad.  By 
retaining  some  of  the  descriptive  terms  and  discarding  others  less  exact,  con- 
fusion may  be  overcome  and  a  greater  uniformity  reached.  Sherren  (1906) 
appreciated  the  need  of  clarification  and  suggested  a  re-arrangement  offering  one 
or  two  new  terms,  some  of  which  are  of  distinct  advantage  while  others  are 
lacking  in  histological  accuracy. 

The  terms  neuroplasty  and  neurorrhaphy  have  been  used  to  designate 
almost  any  nerve  operation,  end-to-end  suture,  nerve  crossing,  nerve  flap,  etc., 
and  consequently  may  apply  to  any  form  of  nerve  suture.  In  the  German 
literature  neuroplasty  is  referred  to  occasionally  as  the  Hueter-Czerny  method 
of  nerve  flap  operation,  though  neither  author  originated  the  method,  while  by 
"Bruns  Neuroplasty,"  partial  nerve  suture  is  meant.  Since  neither  neuroplasty 
nor  neurorrhaphy  in  themselves  designate  any  particular  type  of  operation,  it 
would  seem  advisable  to  discard  these  terms  altogether  and  to  use  only  exphcit 
terms  which  indicate  more  precisely  the  method  of  repair,  such  as  nerve  flap, 
nerve  crossing,  etc. 

SPECIFIC  TERMS 
Nerve  Transplantation. — In  the  English,  American,  as  well  as  the  Conti- 
nental hterature,  lack  of  uniformity  has  been  conspicuous,  particularly  in  the  use 
of  the  word  graft.     At  one  time  a  totally  different  meaning  was  given  to  this  word 
by  the  French ,  who  used '  'greffe  nerveuse ' '  for  nerve  implantation ,  as  was  originally 

used  by  Letievant  (1872)  who  first  described  this  method.     Sherren  suggested 

80 


METHODS  OF  NERVE  REPAIR 


8l 


that  the  word  "greffe"  be  omitted  because  it  meant  inplantation  in  French 
hterature  and  transplantation  in  EngUsh  and  American  literature.  However, 
since  this  objection  was  made,  the  French  have  come  to  use  the  word  in  the 
other  sense,  so  that  now  the  term  "nerve  graft"  (greffe  nerveuse)  is  used  univer- 


FiG.  26. — Nerve  transplantation.     Use  of  cable  or  multiple  transplants,  autogenous,  homogenous 

or  heterogenous. 

sally  to  designate  the  interposition  of  a  nerve  segment  between  nerve  ends  and 
has  been  used  by  Duroux  and  Couveur,  Babinski,  Dejerine,  Nageotte,  Gosset 
and  others.  The  word  graft  in  EngUsh  literature,  in  conformity  with  long 
established  usage,  designates  the  transference  of  any  tissue  from  one  site  to 
another — skin  graft,  bone  graft,  etc.,  consequently,  there  is  little  reason  to 
omit  this  word  from  nerve  surgery.  The  terms 
transplant  and  graft  have  been  used  interchange- 
ably, hence  the  use  of  either  would  lead  to  no 
confusion,  though  in  more  recent  literature  the 
term  transplant  has  been  given  the  greater  currency 
and  may  be  preferred.  In  view  of  the  more 
recent  experimental  advances  in  repair  of  nerve  de- 
fects, with  different  varieties  of  grafts,  the  terms 
nerve  graft  or  nerve  transplant  must  be  further  quaU- 
tied  in  order  to  convey  any  concise  meaning.  A  nerve 
transplant  or  graft  may  be  autogenous  (nerve  taken 
from  the  same  individual) ,  homogenous  (nerve  from         ^'°-  27— ^"erve  impknta- 

.     ,.    .  1       ,        r      ^1  •     \  1  ^'^°°-     ^"    ''■"^     implantation 

individual    of    the  same    species),   or    heterogenous  the  funiculi  are  separated  and 

(nerve  taken  from  some  other  species).     It  may  be  the  nerve  is  implanted  in  the 

.,,,.■  1       1     r       1  1    /         •         •  space    between    the   funiculi. 

either  living  or  dead,  fresh  or  preserved  (on  ice,  m  By  implantation  between  the 

alcohol,  etc.),  a  single  strand  or  multiple  strands,      funiculi  neuraxes  are  not  cut 

,,,,.,.  11     1   a      i_i      i  1       ill         1-11  '''"d  neurotization  of  the  im- 

the  latter  being  called     cable  transplant     or  '•  cable-     ^^^„,^^  ,„d  d„^^  „„^  ^^^^  p,,^^^ 

graft."    (See  Fig.  26.)  unless  neuraxes  are  accident- 

Nerve  Implantation. — Sherren  has  suggested  that     ''  >  '^^  • 
the  term  nerve  anastomosis  be  used  to  designate  the  operation  of  nerve  implan- 
tation, " greffenerveusc"  of  Letievant,  and  in  the  German  " Nervenpfropfung." 
Sherren  also  includes  under  anastomosis  the  operation  whereby  a  small  flap  is 


82 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


raised  in  a  sound  nerve  and  sutured  to  the  distal  end  of  a  severed  nerve.  From  an 
anatomical  standpoint,  this  last  operation  is  quite  a  different  procedure  from 
simple  implantation.  In  this  the  severed  end  of  an  injured  nerve  is  brought  in 
direct  apposition  with  the  cut  end  of  a  nerve  flap  in  which  there  are  severed 
neuraxes,  whereas,  in  implantation,  whether  the  central,  peripheral  or  both  ends 

be  implanted,  the  severed  end  of  the  injured 
nerve  is  implanted  in  a  slit  between  the  funiculi 
of  the  sound  nerve.  (See  Fig.  27.)  These 
funiculi  may  not  be  cut  and  the  neuraxes,  there- 
fore, do  not  escape  to  grow  into  the  implanted 
nerve  except  when  they  are  accidentally  cut. 
The  severed  nerve  ends  lie  between  funiculi  and 
not  against  severed  neuraxes,  as  is  the  case  when 
a  flap,  either  large  or  small,  is  raised  from  a  sound 
nerve  and  sutured  to  the  distal  end  of  a  severed 
nerve.     Thus,    from    the  standpoint  of  nerve 


Fig-  29  Fig.  30 

-An  end-to-end  suture  of  the  distal  end  of  one  nerve  to 


Fig.  28 

Fig.  28. — Complete  nerve  crossin; 
the  central  end  of  another. 

Fig.  29.— Partial  nerve  crossing.  By  raising  a  small  flap  and  direct  end-to-end  suture  of  the  flap 
to  the  nerve,  better  approximation  is  obtained  and  better  downgrowth  of  neuraxes  secured  than  by 
implantation. 

Fig.  30. — Partial  nerve  crossing,  wrongly  called  implantation.  Neuraxes  have  been  cut 
before  implantation  has  been  done.     This  method  consequently  is  partial  nerve  crossing. 


regeneration,  the  term  nerve  anastomosis  as  suggested  by  Sherren  would 
include  two  distinct  surgical  procedures,  histologically  different.  It  might 
tend   toward  a  more  definite  conception  of  nerve  repair  were  the  operation 


METHODS  OF  NERVE  REPAIR 


83 


of  raising  either  a  large  or  small  flap  from  a  sound  nerve  with  end-to-end  suture 
of  it  to  a  severed  nerve  to  be  included  under  nerve  crossing. 

Nerve  crossing  is  perhaps  the  most  descriptive  term  in  use.  By  it  is  meant 
the  union,  end  to-end,  of  the  central  end  of  one  nerve  with  the  distal  end  of  another. 
This  would  he" complete  nerve  crossing."  (See  Fig.  28.)  When  a  flap  is  raised 
from  a  sound  nerve  and  sutured  to  the  end  of  another,  the  operation  should  be 
designated  as  "partial"  or  "incomplete  crossing."  (See  Fig.  29.)  Both  pro- 
cedures have  the  same  anatomical  basis  and  should  be  included  under  the 
same  term. 

Nerve  Implantation. — Since  the  operation  of  partial  nerve  crossing  is 
removed  from  the  category  of  anastomosis  and  placed  in  the  division  of  nerve 
crossing,  it  might  seem  advisable  to  discard  altogether  the  term  anastomosis,  and 
to  revive  the  use  of  the  term  "nerve  iinplaulalion"  to  designate  the  implantation 
into  a  sound  nerve  of  either  the  central,  peripheral  or  both  ends  of  an  injured 
nerve. 

Implantation  may  become  nerve  crossing  if  the  funiculi  of  the  sound  nerve 
are  severed  and  grow  into  the  implanted  nerve.     (See  Fig.  30).     However,  if 
true  implantation   technic  is   practiced    as  advocated  by  the  author  of  the 
implantation  method  the  funiculi  are  pushed  aside   and 
not    injured.     When     the    central    and    distal    ends    are 
implanted  it   was    supposed     that    the    neuraxes   of   the 
central  grew  into  the  endoneural  and    perineural  spaces 
until  they  reached  the  distal  implanted  end  and   thus  re- 
gained their  own  nerve  trunk.     While  I  do  not  agree  that 
this  takes  place,  this  is  what  is  said  to  follow  such  double 
implantations.     Consequently,  this  method  is  not  in  any 
sense  nerve  crossing  and  must  be  differentiated  from  nerve 
crossing  by  use  of  the  term  implantation. 

Suture  a  distance  is  used  to  designate  suture  as  de- 
scribed by  Assaky  (1886).  whereby  the  nerve  ends  are 
brought  into  alignment  but  not  in  contact  and  held  in  align- 
ment by  a  network  of  catgut  or  silk  sutures  supposedly  form- 
ing a  scaffolding  for  the  downgrowth  of  neuraxes. 

End-to-end  Suture. — In  addition  to  the  above  the  descriptive  term  end- 
to-end  suture  should  be  continued  in  use  to  indicate  the  suture  of  a  severed 
nerve  when  the  cross  areas  of  both  the  central  and  peripheral  ends  of  the  nerve 
are  brought  together.       (See  Fig.  31.) 


m 


Fic.  3  I  . — X  er  ve 
ends  prepared  for  end- 
to-end  suture — always 
the  method  of  choice. 


84 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


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86  SniGICAL   AND   MECHANICAL    TREATMENT   OF   PERIPHEIL\L   NER\rES 

Nerve  suture  may  also  be  further  qualified  according  to  the  time  at  which 
suture  is  done.  Those  sutured  at  the  time  the  primary  wound  is  first  treated 
surgically  have  been  called  primary  sutures,  while  those  repaired  after  the 
original  wound  has  healed,  no  matter  how  great  the  interval  between  injury 
and  repair,  secondary  sutures. 

In  resume  the  terms  retained  here  are : 

A.  Priman,-  or  secondary  nerve  suture. 

B.  End-to-end  suture,  partial  or  complete. 

C.  Nerve  graft  or  nerve  transplantation,  furthur  qualified  as  autogenous, 
homogenous  or  heterogenous,  fresh  or  preserved,  single  or  cable  graft. 

D.  Nerve  crossing,  partial  or  complete. 

E.  Nerve  implantation,  distal  end  only  or  both  central  and  distal. 

F.  Nerve  flaps —  formed  from  central  end,  or  distal  end  or  from  both. 

G.  Suture  a  distance. 

METHODS  TO  BE  DISCARDED 

Recent  experiences,  both  cKnical  and  experimental,  have  offered  oppor- 
tunity to  evaluate  various  surgical  procedures  emploj^ed  in  the  treatment  of 
nerve  injuries.  Carefiil  study  of  chnical  results  has  sho-mi  that  methods 
most  successful  experimentally  were  also  most  successful  clinicaUj^,  and  con- 
versely, that  methods  clinically  unsuccessful  experimentally  were  of  least 
value.  While  it  may  be  true  that  it  is  not  always  possible  to  reproduce  experi- 
mentally conditions  comparable  to  those  found  in  the  himian,  j^et  it  has  been 
shown  that  methods  of  little  value  under  the  more  favorable  circumstances 
of  experimental  conditions  were  of  as  Httle  or  less  value  when  appUed  cHnicaUy. 
By  constant  checking  of  the  experimental  with  the  clinical  and  the  clinical 
with  the  experimental,  it  has  been  possible  to  eliminate  methods  which  have 
demonstrated  their  futihtj-.  Unfortunately,  in  the  years  past  the  clinical 
lagged  notabty  behind  the  experimental.  But  at  present  the  chnical  has  again 
caught  up  with  the  experimental  and  the  two  have  progressed  co-ordinately. 

As  a  result  of  both  clinical  and  experimental  studies,  some  methods  maj' 
safely  be  discarded,  either  as  valueless,  or  as  offering  such  sUght  opportunitj^ 
for  successful  regeneration  that  methods  more  successful  should  be  used  in 
their  stead. 

Nerve  Flap  Method. — Among  the  procedtires  to  be  discarded  is  the  ''flap 
metlwd"  or  "suture  a  Idmbeaux^'  first  described  by  Letievant  (1872).     (See 


METHODS  OF  XERVE  REPAIR 


87 


L 


/^ 


Fig.  32.)  In  a  critical  review  of  all  cases  published  up  to  1914.  from  the  first 
operation  by  Letievant,  Stookey  (1919)  has  shown  that  not  a  single  case,  so 
far  as  one  was  able  to  judge  from  the  pubUshed  reports,  gave  any  evidence  of 
successful  regeneration,  while  the  two  cases  which  were  responsi- 
ble more  than  any  others  for  a  continuation  of  this  method, 
Tillmanns'  (1885)  and  Kenneth  Mackenzie's  (1909-1918),  were 
totally  lacking  in  evidence  of  satisfactory  regeneration.  (See 
Chart  I.) 

In  Tillmanns'  case  the  greatest  part  of  the  disabiHty  was 
due.  not  to  paralysis  of  the  flexor  muscles,  since  the  median  and 
ulnar  nerves  were  injured  at  the  wrist,  below  the  level  at  which 
the  flexor  muscles  receive  their  nerve  supply,  but  rather  to  the 
fact  that  these  tendons  were  bound  down  in  a  "tendonous  knot" 
which  was  freed  at  the  operation  when  nerve  flaps  were  per- 
formed on  both  the  median  and  ulnar  nerves.  The  only  improve- 
ment reported  in  this  case  was  an  increase  in  the  range  of 
motion  of  the  fingers  so  that  the  patient  was  able  to  perform 
such  total  movements  as  picking  up  a  glass  or  holding  a  pen 
lightly,  etc.  This  increase  of  flexor  movement  is  rather  to  be 
attributed  to  the  freeing  of  the  tendons  than  to  bridging  irrele- 
vant nerve  defects  by  means  of  nerve  flaps. 

Kenneth  ^lackenzie's  case  of  tumor  of  the  sciatic  nerve, 
from  which  "10.75  inches  of  the  sciatic  (was  excised)  in  toto  from 
the  lower  border  of  the  gluteus  maximus  to  i  inch  above  the  pop- 
liteal space,"  and  the  defect  bridged  by  two  flaps  taken  from  the 
peripheral  segments  offered  no  satisfactory  evidence,  so  far  as  the  report 
showed,  of  either  motor  or  sensorv  recoverv. 


V-^ 


r 


Fig.  32. — 
Flaps  wheth- 
er from  the 
central,  distal 
or  both  ends 
should  never 
be  used  to 
bridge  nerve 
defects. 


TECHNICAL  CONSIDERATIONS  OF  NERVE  FLAP  METHOD 


Central  Flap. — By  splitting  or  cutting  a  flap  from  the  central  portion  of  the 
nerve  a  definite  number  of  dowmcoursing  neuraxes  are  permanently  destroyed 
in  proportion  to  the  width  of  the  flap.  It  has  been  argued  by  Stoffel  (1913) 
that  each  funiculus  has  a  definite  course  within  the  nerve  trunk,  extending  from 
the  plexus  to  its  ultimate  distribution  in  the  periphery.  \Vhile  this  may  not 
be  true,  yet  in  certain  portions  there  are  definite  nerve  paths  which  are  irrepar- 
ably destroyed  by  cutting  flaps  from  the  nerve  trunk,  and  their  subsequent 


88  SURGICAL   AND    MECHANICAL   TREATMENT    OF   PERIPHERAL   NERVES 

regeneration  is  rendered  impossible.  In  flap  operations  in  which  two  flaps  are 
made  from  the  same  stump,  one-quarter  to  one-third  of  the  nerve  or  more  is 
removed  from  each  side  of  the  trunk.  This  damage  done  to  the  central  nerve 
end,  from  which  regeneration  must  take  place,  is  considerable. 

Were  the  flap  cut  from  the  area  of  an  internal  nerve  plexus,  or  central  to  it, 
greater  damage  would  be  done  the  nerve  trunk  than  if  the  flap  were  made  below 
a  plexus.  In  either  instance,  considerable  permanent  longitudinal  loss  of 
substance  ensues.  The  neuraxes,  central  to  the  site  from  which  the  flap  is  cut, 
will  attempt  to  regenerate.  The  conducting  paths  having  been  removed, 
these  regenerating  neuraxes  are  then  apt  to  grow  out  into  the  surrounding 
tissue  or  they  may  coil  upon  themselves  and  form  a  lateral  neuroma  on  the  nerve 
trunk  itself. 

Thus,  if  one-third  to  one-half  the  diameter  of  the  nerve  trunk  be  cut  as  a 
flap,  one-third  to  one-half  of  the  neuraxes  are  permanently  eliminated  and  are 
deprived  of  any  possibility  of  reaching  the  distal  stump. 

Dittel  (1891)  and  others  thought  that  by  turning  down  a  flap  from  the 
central  stump  neuraxes  were  carried  across  the  defect  and  that,  at  the  point  of 
suture,  union  of  the  central  neuraxes  with  the  peripheral  would  take  place  or 
further  growth  of  these  neuraxes  follow.  Such,  of  course,  is  not  the  case.  The 
central  flap,  when  cut  centrally  and  turned  down,  is  nothing  more  than  a 
degenerated  segment  of  nerve.  Since  the  neuraxes  within  the  nerve  flap  degen- 
erate, the  only  tissue  bridging  the  nerve  defect  is  connective  tissue  in  which  the 
neuraxes  have  undergone  degeneration  and  the  sheath  cells  of  Schwann  pro- 
liferation; showing  in  short  the  same  Wallerian  degeneration  as  occurs  in  the 
severed  portion  of  any  peripheral  nerve.  The  central  flap  is  bent  down  at  a 
rather  sharp  angle  upon  itself  over  its  connection  with  the  central  stump,  and 
on  account  of  the  angulation  really  offers  very  slight  opportunity  for  the 
down-growing  neuraxes  to  make  their  way  into  the  few  conducting  paths 
offered.  Thus,  these  paths  within  the  flaps  mechanically  are  so  placed  that 
they  not  only  do  not  come  in  contact  with  the  severed  neuraxes  but  are 
practically  unable  to  reach  them.  Hence,  the  flaps  do  not  serve  the  purpose 
for  which  they  are  intended  and,  furthermore,  inflict  permanent  damage  to  the 
nerve  trunk. 

Peripheral  Flap. — Flaps  cut  from  the  distal  stump  deprive  the  peripheral 
nerve  of  a  deiinite  portion  of  its  conducting  paths.  In  Mackenzie's  case  a  flap 
was  turned  up  from  both  the  tibial  and  peroneal  nerves,  16  inches  long, 
and   "a  shade  less  than  half  its  diameter.''     By  so  doing  he  removed  per- 


METHODS    OF   NERVE    REPAIR  89 

manently  the  possibility  of  regeneration  in  the  area  of  the  leg  and  foot  to  which 
their  funicuU  would  have  gone.  A  still  greater  damage  is  done  by  severing 
numerous  muscular  branches  from  the  nerve  trunk.  One  need  only  recall  the 
anatomy  of  the  tibial  and  peroneal  nerves,  and  the  numerous  muscular  branches 
which  lead  from  them,  to  realize  the  extent  of  permanent  damage  done  in  the 
formation  of  such  a  flap.  When  a  branch  from  the  nerve  trunk  to  the  muscle 
is  thus  removed  and  taken  altogether  out  of  the  held,  the  down  growing  neuraxes 
are  deprived  of  any  possible  path  from  the  remaining  nerve  trunk  to  the  muscle. 
This  is  an  extremely  important  point.  Even  were  regeneration  to  take  place 
and  neuraxes  grow  down  into  the  distal  segment  they  would  find  )io  paths  from 
the  nerve  trunk  to  the  adjacent  muscles.  The  muscles  thus  severed  from  their 
nerve  branches  would  remain  permanently  without  the  possibility  of  neurotiza- 
tion. It  is  of  course  obvious  that  the  peripheral  flap  is  also  a  degenerated  nerve 
segment,  the  same  as  the  distal  segment  from  which  it  is  cut. 

The  method  of  uniting  the  central  or  peripheral  flaps  to  the  other  stump 
would  be  of  importance  if  the  flap  method  were  of  value.  The  severed  end  of 
the  flap  may  be  brought  into  apposition  with  the  freshened  central  or  peripheral 
end  in  order  that  the  downgrowing  neuraxes  might  come  in  definite  contact 
with  what  conducting  paths  the  flap  offers.  "To  insert  the  flap  into  a  spht" 
in  the  central  or  peripheral  stump  merely  places  the  proffered  conducting- 
paths  hekveen  funiculi  and  out  of  contact  with  their  ends.  For  proper  down- 
growth  severed  neuraxes  should  lie  in  as  close  contact  as  possible  with  the 
conducting  paths  used  to  bridge  the  gap.  Unless  this  is  accomplished,  they 
become  lost  and  dispersed  in  the  surrounding  connective  tissue.  Thereby 
the  number  of  available  neuraxes  already  reduced  in  the  formation  of  flaps  is 
further  diminished,  and  even  the  remote  possibility  of  a  few  neuraxes  finding 
their  way  down  is  removed  by  such  union. 

It  is  possil)le  that  the  nerve  flaps  may  be  cut  so  nearly  completely  from 
the  parent  trunk  that  they  lie  in  fairly  good  apposition  with  the  nerve  end, 
thus  in  effect  becoming  practically  a  free  nerve  transplant.  Such  a  flap  may 
then  transmit  neuraxes,  with  all  the  limitations  of  a  single  graft  as  compared 
with  multiple  grafts,  but  with  the  additional  disadvantage  of  injury  to  the 
nerve  trunk  from  which  regeneration  is  to  take  place.  An  occasional  case 
may  be  successful  if  the  flaps  are  thus  made.  The  method,  however  done, 
should  be  condemned,  since  a  graft  taken  from  any  skin  nerve  will  serve 
equally  well  or  better  in  that  end-to-end  approximation  may  be  more  accu- 
rately obtained  and  no  damage  done  the  parent  nerve. 


90  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL   NERVES 

The  use  of  nerve  flaps  to  bridge  defects  is  based  probably  upon  the  close 
resemblance  of  a  nerve  to  a  tendon  in  its  gross  appearance.  Bridging  defects 
in  tendons  by  means  of  flaps  is  well  founded  because  histologically  the  tendon 
is  made  up  of  one  tissue — the  densest  variety  of  white  fibrous  tissue.  It  is 
a  tissue  unit  in  itself.  Healing  by  primary  union  establishes  complete  ana- 
tomical continuity.  On  the  other  hand,  a  nerve,  while  grossly  similar  in  appear- 
ance, histologically  is  made  up  of  two  distinct  elements:  the  conducting  tubes 
and  the  neuraxes  from  the  ventral  column  or  dorsal  spinal  ganglia  cells  which 
lie  within  these  tubes.  Severed  neuraxes  must  grow  down  from  the  central 
stump.  The  sheath  cells  of  Schwann  united  to  form  syncytial  strands  serve 
as  conducting  paths.  Thus  when  two  flaps  are  brought  together  anatomical 
union  takes  place  as  in  a  tendon,  but  neurotization  does  not  until  central  neuraxes 
liave  grown  into  tlie  distal  stump. 

From  this  it  will  be  seen  that  flap  operations,  either  central  or  peripheral, 
cause  permanent  and  irreparable  damage  to  both  the  central  and  peripheral  nerve 
ends,  utilize  degenerated  nerve  segments  which  offer  relatively  negligible  con- 
ducting paths  for  the  severed  neuraxes,  and  that  immediate  union  of  nerve 
flaps  cannot  establish  conductivity. 

Experimental  Evidence. — The  above  conclusions  are  ably  proved  by  the 
experimental  work  of  Huber  (1895).  Seven  flap  operations  were  performed  on 
the  ulnar  nerve  in  dogs.  By  means  of  both  central  and  peripheral  flaps,  defects, 
varying  from  5  to  6  cm.,  were  bridged.  The  animals  were  killed  at  intervals 
up  to  a  hundred  and  forty-seven  days,  the  first  on  the  sixty-fourth  day, 
and  thus  both  late  and  early  stages  of  repair  were  investigated. 

When  examined  physiologically  and  histologically  in  no  instances  were 
any  evidences  of  regeneration  found  neither  within  the  flaps  nor  the  distal 
portion  of  the  nerve.  "In  sections  through  the  regions  of  the  down-turned 
flaps  the  collapsed  sheaths,  containing  a  small  amount  of  nucleated  proto- 
plasm, were  found.     In  these  no  evidences  of  regeneration  were  seen." 

Because  of  a  continuation,  perhaps,  of  blood  and  lymph  supply  to  the 
flaps,  Huber  found  that  they  underwent  degeaeration  somewhat  slower  than 
a  free  transplanted  nerve  segment.  The  rate  of  degeneration  of  the  flap  was 
the  same  as  that  found  in  the  peripheral  portion  of  the  divided  nerve. 

Thus,  from  both  experimental  and  clinical  evidences,  Stookey  concluded 
that  there  is  "insufficient  and  inadequate  data  to  warrant  a  continuation  of 
the  nerve  flap  method  in  the  surgical  repair  of  nerve  defects,  and  that  the 
method  should  be  discarded  in  peripheral  nerve  surgery." 


METHODS    OF    NERVE    REPAIR  9I 

SUTURE  A  DISTANCE 

In  order  to  supply  a  scaffolding  for  the  downgrowing  neuraxes  Assaky  (1886) 
interposed  between  divided  nerve  ends,  from  which  approximately  3  cm.  was 
excised,  a  cable  of  catgut  fixed  with  sutures  to  both  the  central  and  peripheral 
nerve  stumps.  In  all  live  experiments  originally  performed  by  Assaky,  regener- 
a  t  ing  neuraxes  were  found  both  within  the  tissues  between  the  nerve  segments  and 
in  the  distal  segment.  Huber  (1895)  repeated  these  experiments  in  a  more 
thorough  manner,  excising  a  longer  segment  from  the  nerve,  so  that  the  neuraxes 
would  have  farther  to  travel,  and  found  that  in  two  out  of  three  experiments, 
observed  more  than  one  hundred  and  twenty  days,  physiological,  as  well  as 
histological,  evidence  of  regeneration  was  present ;  while  in  the  third,  no  evidence 
of  regeneration  either  physiological  or  histological  was  obtained.  In  the  latter 
experiment,  catgut  remains  were  still  present  between  the  nerve  segments 
though  the  duration  of  the  experiment  was  one  hundred  and  forty  days.  In 
experiments  of  less  duration,  four  early  and  two  late,  the  catgut  was  gradu- 
ally absorbed  and  replaced  by  connective  tissue  through  which  the  down- 
growing  neuraxes  had  to  pass  to  reach  the  peripheral  stump.  The  invading 
connective  tissue  assumes  a  strand-like  arrangement  similar  to  the  strands  of 
catgut,  thus  forming  a  network  of  connective  tissue,  younger  and,  therefore, 
looser  than  the  surrounding  connective  tissue,  as  a  scaffolding  for  the  down- 
growing  neuraxes.  The  catgut  strands  resist  connective  tissue  invasion  for  a 
short  period  so  that  when  finally  replaced  this  connective  tissue  is  younger  than 
the  surrounding  scar.  Downgrowth  through  this  young  and  loose  connective 
tissue  offers  less  resistance  than  through  older,  denser  connective  tissue.  Huber 
felt  that  in  the  experiment  in  which  the  catgut  was  not  absorbed  and  in  which  no 
regeneration  had  occurred  that  the  catgut  may  have  served  as  an  obstacle  to  the 
downgrowth. 

Clinically  cases  have  been  recorded  in  which  successful  regeneration  has 
taken  place;  however,  the  reports  are  too  meager  to  admit  of  a  thorough  critical 
review  being  made,  and  more  recently  most  surgeons  have  recognized  that 
though  downgrowth  may  take  place  following  "suture  a  distd)icc,"  other  methods 
offer  greater  opportunities  for  bridging  nerve  defects. 

It  is  obvious  that  when  downgrowth  must  depend  upon  the  haphazard 
formation  of  an  intervening  scar  scaffolding,  too  precarious  a  network  for  suc- 
cessful downgrowth  is  offered.  Not  only  is  the  directing  influence  not  predeter- 
mined as  in  other  methods,  but  the  density  of  scar  tissue,  increasing  with  time, 
might  eventually  strangle  the  neuraxes  or  otTer  too  great  an  impediment  to 


92  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

further  downgrowth,  especially  if  a  long  distance  is  to  be  bridged.  Since  a 
better  means  of  supplying  a  scaffolding  for  downgrowing  neuraxes  than  scar 
tissue  is  available,  suture  a  distance  should  be  abandoned  as  a  method,  clinically 
only  remotely  possible  of  success. 

NERVE  IMPLANTATION 

As  the  result  of  Hoffmann's  strong  championship  of  this  form  of  bridging 
nerve  defects,  nerve  implantation  has  been  rather  extensively  used  in  Germany. 
This  method  is  originally  the  work  of  Letievant  (1873),  and  was  later  modified 
by  Tillmanns  (1885)  so  as  to  be  applicable  to  two  parallel  nerves.  Letievant 
suggested  that  the  distal  segment  of  a  severed  nerve  may  be  implanted  into  an 
adjacent  sound  nerve,  after  removing  the  epineurium  from  the  latter  at  the  site 
of  implantation.  Despres  (1876)  was  the  first  to  adopt  this  method  clinically, 
and  the  first  report  of  a  successful  case  was  by  Sick  and  Sanger  (1897).  In 
their  case  not  nerve  implantation  was  done  but  partial  nerve  crossing,  since  a 
flap  of  the  median  nerve  was  raised  and  sutured  to  the  musculospiral  with  return 
of  function  twenty-seven  months  later  in  all  of  the  extensors  except  those  of  the 
thumb.  Tillmanns  modified  the  method  so  that  when  two  parallel  nerves 
were  severed  at  different  levels  a  cross  suture  could  be  performed  upon  the  two 
long  stumps  while  the  two  short  stumps  were  implanted  into  the  sutured  long 
ones.  This  latter  method  really  consists  of  two  different  types  of  operation, 
end-to-end  nerve  crossing  and  implantation. 

Ample  experimental  and  clinical  observations  have  substantiated  that  end- 
to-end  nerve  crossing  permits  excellent  regeneration  of  the  neuraxes  within  the 
peripheral  segment.  However,  such  favorable  results  do  not  follow  implanta- 
tion, either  clinically  or  experimentally.  Powers'  (1904)  review  attril)uted 
about  50%  successes  to  the  implantation  method,  and  Sherren  (1908)  found  that 
out  of  twelve  cases  observed  sufficiently  long  "only  two  were  failures;  some 
improvement  took  place  in  all  the  others."  Such  conclusions  hardly  seem 
warranted  by  the  reports  of  the  cases.  Of  the  twelve  cases  in  Sherren's  report 
which  had  been  observed  long  enough  for  recovery,  only  two  offered  sufficient 
evidence  to  warrant  the  assumption  of  improvement;  in  the  remaining  ten 
either  no  result  was  given  or  movements  were  cited  as  evidence  of  improvement, 
which  may  be  accompUshed  even  though  severance  of  the  nerve  be  complete. 
As  has  already  been  stated,  nerve  implantation  is  successful  only  in  proportion 
to  the  number  of  neuraxes  intentionally  or  accidentally  severed  at  the  time  of 
implantation.     If  true  implantation  technic  is  used,  as  indicated  by  the  advo- 


METHODS  OF  NERVE  REPAIR  93 

cates  of  this  method,  only  a  slit  is  made  in  the  adjacent  nerve  and  the  distal 
segment  is  implanted  into  the  slit.     (See  Fig.  27.) 

By  such  implantation  of  the  distal  segment  of  the  severed  nerve,  the 
theoretical  intention  is  that  the  neuraxes  of  the  sound  nerve  will  grow  down 
paths  offered  l:)y  the  implanted  nerve.  However,  as  has  been  said  if  the  funiculi 
are  merely  separated  and  the  implantation  made,  no  funiculi  are  cut  and  the 
conducting  paths  of  the  implanted  segment  abut  into  the  endoneural  connec- 
tive tissue  between  the  funiculi  where  there  are  no  neuraxes  available  for 
downgrowth. 

When  both  the  central  and  peripheral  segments  are  implanted  it  is  pre- 
sumed that  the  neuraxes  from  the  central  stump  will  grow  between  the  funiculi 
of  the  nerve  trunk,  using  the  nerve  trunk  as  a  scaffolding,  and  reach  the  distal 
implanted  segment.  Apparently  the  object  of  such  double  implantation  is  to 
use  the  endoneural  spaces  as  a  scaffolding.  However,  instead  of  growing  down, 
the  implanted  central  end  forms  a  small  neuroma  and  the  few  outgrowing 
neuraxes  are  lost  and  sufficient  downgrowth  does  not  occur.  Thus,  by  growing 
in  the  connective  tissue  between  the  funiculi,  the  neuraxes  have  little  chance  to 
reach  the  distal  implanted  segment.  The  fate  of  the  distal  implanted  segment 
has  already  been  discussed. 

In  the  majority  of  instances  whatever  success  has  been  reported  from 
implantation  has  been  due  to  ingrowth  of  neuraxes  from  those  funiculi  inci- 
dentally cut  at  the  time  of  implantation,  as  in  the  case  of  Sick  and  Sanger  which 
was  in  reality  a  partial  nerve  crossing.  In  other  words,  implantation  is  success- 
ful in  so  far  as  it  is  partial  nerve  crossing,  though  imperfectly  accompKshed. 
Hence,  it  would  be  better  to  perform  partial  nerve  crossing  in  the  first  place, 
care  being  paid  to  supply  an  appropriate  number  of  neuraxes  and  to  insure  more 
exact  end-to-end  apposition.  Huber  (1895)  found  experimentally  that  im- 
planted nerve  segments  showed  neither  physiological  nor  histological  evidence 
of  downgrowth,  while  end-to-end  nerve  crossing  gave  evidences  of  functional 
return. 

It  must  be  recalled  that  in  implantation  of  either  the  distal  or  central 
segment,  permanent  injury  may  be  done  the  parent  nerve,  if  the  funiculi  inci- 
dentally cut  happen  to  be  motor  funiculi  having  already  been  segregated  into 
definite  paths  destined  for  a  definite  muscle  or  muscle  group  such  as  exist  in  the 
vicinity  near  which  branches  are  given  off. 

Consequently,  since  nerve  implantation  offers  comparatively  little  oppor- 
tunity for  successful  downgrowth,  certainly  less  than  other  available  methods. 


94  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

preference  should  be  given  those  procedures  which  present  fewer  obstacles  and 
better  facilities  for  downgrowth  and  do  not  entail  injury  to  adjacent  sound 
nerves. 

METHODS  TO  BE  USED 
End-to-end  Suture 

The  method  of  nerve  suture  most  desirable  is  that  which  approaches  the 
nearest  to  the  normal  anatomical  arrangement  of  the  nerve  injured  and  unites 
a  distal  end  of  a  nerve  with  a  central  end,  having  identical  segmental  and  inter- 
segmental connections  in  the  cord  and  connections  with  identical  higher  centers 
as  formerly  existed.  The  nearest  approach  to  this  aim  is  end-to-end  suture 
of  a  divided  nerve.  Even  with  end-to-end  suture  the  ideal  is  not  attained, 
since  in  many  situations  it  is  impossible  to  bring  identical  funicular  paths  in 
approximation.  The  ideal  would  be  so  to  suture  a  severed  nerve  as  to  bring 
identical  funicular  paths  together  so  that  identical  peripheral  connections,  both 
motor  and  sensory  be  made  by  processes  of  identical  cells  of  the  ventral  gray 
column  and  dorsal  ganglia.  Were  such  regeneration  made  possible  the  ideal 
suture  would  be  attained.  Rearrangement  of  the  fibers  within  the  plexuses 
of  the  nerve  trunk  would  be  unnecessary;  reflex  paths  would  be  unaltered  and 
unchanged  connections  with  the  associated  centers  maintained. 

End-to-end  suture  can  attain  this  ideal  result  only  extremely  rarely  if  ever, 
yet  this  end  must  be  the  goal  which  we  must  seek.  By  accurate  apposition  of 
the  nerve  ends  without  axial  rotation  and  with  a  minimum  of  trauma  and  con- 
nective tissue  formation  the  best  results  are  obtained.  Only  in  rare  instances  is 
separate  funicular  suture  possible.  In  one  case  of  tumor  of  the  median  nerve  the 
funiculi  had  been  dissected  free  by  the  tumor  into  separate  bundles  by  stretch 
ing  of  the  perineural  connective  tissue  so  that  an  ideal  situation  for  individual 
funicular  suture  presented,  and  this  was  readily  performed.  Langley  and 
Hashimoto  (1917)  advocated  individual  funicular  suture  but  felt  that  the  extra 
traumatism  incidental  with  such  suture  outweighed  the  advantages. 

In  order  to  overcome  the  misdirection  of  neuraxes  into  channels  foreign 
to  them,  Nageotte  (1918)  proposed  that,  if  end-to-end  suture  were  done  without 
bringing  the  nerve  ends  into  close  apposition,  but  so  as  to  leave  a  space  of  3  to 
4  mm.,  rearrangement  of  the  neuraxes  into  their  proper  paths  might  take 
place.  Whereas  if  the  suture  were  made  so  that  the  funiculi  are  brought  end 
on  end,  with  funiculus  A  opposite  funiculus  B  instead  of  A,  downgrowth  from 
A  into  B  must  necessarily  follow.     Nageotte  felt  that  by  leaving  a  small  space 


METHODS  OF  NERVE  REPAIR 


95 


between  the  funiculi  of  the  central  and  distal  segments  rearrangement  of  the 
fibers  might  take  place  at  the  point  of  suture  and  the  fibers  find  their  proper 
channels.  This  idea  is  seductive  but  it  has  not  been  shown  that  such  rearrange- 
ment at  the  point  of  suture  takes  place,  while  the  increased  amount  of  scar 
tissue  wliich  forms  between  the  nerve  ends  is  a  serious  drawback  and  hemor- 
rhage from  nerve  ends  cannot  be  checked  unless  the  ends  be  brought  in  apposi- 
tion. Blood  between  the  nerve  ends  always  increases  materially  the  amount  of 
scar.  It  is  of  course  true  that  the  sutures  should  not  be  drawn  too  tight  so  as 
to  squash  the  nerve  ends,  but  only  sufficiently  to  bring  the  funiculi  in  contact. 


Fig-  33-  Fig.  34. 

Figs.  33  and  34. — Methods  of  end-to-end  suture  which  should  not  be  used.  When  nerve  ends 
are  cut  obliquely  or  a  wedge  removed  greater  damage  is  done,  more  scar  is  liable  to  form  between 
the  nerve  ends,  and  funicular  approximation  cannot  be  accurate. 


Exact  apposition  of  the  funiculi  minimizes  the  amount  of  connective  tissue 
formation,  while  accurate  union  of  the  epineurium  prevents  connective  tissue 
invasion  from  the  surrounding  tissues. 

It  is  obvious  that  union  of  the  nerve  trunk  by  primary  intention  occurs 
only  for  the  connective  tissue  elements,  whereas  the  neuraxes  must  grow  out 
centrally  and  penetrate  through  the  layer  of  connective  tissue  union.  Con- 
sequently, methods  should  be  used  which  minimize  the  extent  of  connective 
tissue  formation. 

Oblique  suture  and  inverted  V  methods  of  end-to-end  suture  (see  Figs. 
33  and  34)  are  not  suitable  for  nerves,  since  they  prevent  accurate  funicular 
indentification  and  suture,  and  increase  the  amount  of  connective  tissue 
between  nerve   ends.     These  methods  have  been   taken   over   from   tendon 


96  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

surgery  and  while  perhaps  admirable  for  tendons  they  are  not  adapted  to 
nerves. 

End-to-end  suture  is  the  method  of  choice  and  should  be  done  whenever 
possible,  however,  if  too  great  a  sacrifice  of  other  important  principles  of  nerve 
surgery  must  be  made  in  order  to  bring  the  ends  together  other  means  of  su- 
ture must  be  employed.  The  methods  available  to  obtain  end-to-end  union 
and  their  limitations  are  described  later.     (See  p.  103.) 

Nerve  Crossing 

Nerve  crossing,  partial  or  complete,  as  a  means  of  re-estabhshing  nerve 
function  may  be  indicated  when  it  is  not  possible  to  reunite  the  ends  of  a  severed 
nerve,  providing  that  the  nerve  used  to  furnish  neuraxes  to  the  distal  segment 
can  be  spared  without  too  great  physiological  loss  or  inconvenience.  The 
nerve  used  should  have  close  correspondence  in  function;  a  motor  with  a 
motor,  a  sensory  with  a  sensory,  and  a  mixed  nerve  with  a  mLxed  nerve.  The 
closer  the  nerves  are  associated  functionally  in  their  peripheral  distribution, 
by  reflex  collaterals  and  with  higher  centers  centrally,  the  better  are  the  ulti- 
mate results,  especially  if  partial  nerve  crossing  is  done.  The  synergic  action 
of  muscle  groups  is  dependent  partly  on  the  proprioceptive  impulses  from  the 
muscles,  etc.,  so  that  less  re-education  of  nerve  centers  may  be  required  after 
total  than  after  partial  crossing,  since  in  partial  nerve  crossing  impulses  from 
both  old  and  new  groups  are  carried  simultaneously  to  the  same  centers, 
and  confusion,  therefore,  is  more  apt  to  occur. 

The  co-ordinate  use  of  muscle  groups  thus  abnormally  innervated  depends 
among  other  things  on  the  proper  co-ordination  of  the  proprioceptive  stimuli. 
If  these  impulses  reach  normal  connections,  or  are  able  to  form  new  satisfactory 
connections,  muscular  movements  may  be  controlled  both  in  amplitude  and 
force,  and  synergic  action  re-established  in  spite  of  the  crossing  of  the  peripheral 
nerve  fibers.  Crossed  nerves  having  no  correspondence  in  function  may  show 
histological  down-growth  of  neuraxes  into  the  distal  segment  without  physi- 
ological functional  connections  being  made — anatomical  not  physiological 
regeneration.  This  principle  was  recognized  by  Flourens  (1S27)  who  first 
attempted  nerve  crossing,  and  successfully  crossed  the  median  and  muscu- 
lospiral  nerves  in  the  fowl.  Later  he  sutured  the  fifth  cervical  nerve  to  the 
peripheral  end  of  the  vagus  without  functional  result  and  concluded  that  cross 
union  cannot  be  successful  unless  there  is  more  or  less  correspondence  in  the 
organs  supplied  by  the  crossed  nerves.     Bidder  (1842),  Gluge  and  Thiernesse 


METHODS  OF  NERVE  REPAIR  97 

(1859)  and  others  performed  nerve  crossing  using  the  lingual  and  hypo- 
glossal nerves  without  finding  any  functional  reestablishment  and  concluded 
that  functional  return,  following  crossing  of  motor  and  sensory  nerves  was 
improbable. 

Philipeaux  and  Vulpian  (1S70)  on  the  contrary,  claimed  to  have  obtained, 
in  seven  instances,  successful  return  of  function  by  crossing  the  lingual  and 
hypoglossal  nerves.  They  believed  they  were  "able  to  establish  the  trans- 
mission of  impulses  from  the  lingual  to  the  hj-poglossal.  The  movements 
thus  produced  were  not  limited  to  the  corresponding  half  of  the  tongue  but 
involved  movement  of  the  other  half  .  .  .  analogous  to  that  which  results 
from  the  stimulation  of  the  intact  hj^aoglossal  nerve. "  These  authors  concluded 
"that  sensory  fibers  can  tmite  with  motor  fibers  and  that  stimulation  pro- 
duced in  one  set  can  be  transmitted  to  the  other."  These  findings  are  in  di- 
rect contradiction  to  previous  experiments  and  also  are  contradictory  to  all 
later  work. 

Downgrowth  of  neuraxes,  as  has  been  said,  however,  may  take  place 
from  the  central  nerve  stump  of  one  nerve  into  the  distal  segment  of  another, 
even  though  the  central  be  a  motor  and  the  distal  segment  a  sensory  nerve, 
or  vice  versa.  Langley  and  Anderson  (1904)  were  able  to  trace  efferent  fibers 
from  the  anterior  crural  into  the  internal  saphenous  nerve  and  Osborne  and 
Kilvington  (1908),  fibers  from  the  posterior  interosseous  into  the  superficial 
radial.  Following  suture  of  the  hypoglossal  and  lingual  neives,  Boeke  (1913) 
was  able  to  trace  nerve  fibers  into  the  lingual  as  far  as  the  epithelial  cells  of  the 
tongue,  between  which  the  nerve  endings  ramified. 

Thus  the  problem  of  nerve  crossing  is  really  not  one  of  regeneration,  since 
downgrowth  of  neuraxes  will  take  place  providing  the  mechanics  of  the  suture 
are  technically  satisfactory,  but  it  is  rather  one  of  functional  correspondence  and 
the  relative  physiological  expense  of  losing  a  nerve.  Close  correspondence  in 
function  of  any  two  motor  nerves  may,  perhaps,  be  of  little  importance  in  the 
re-establishment  of  gross  movements  of  large  muscles;  but  for  finer  movements, 
such  as  those  of  the  face,  many  of  which  are  associated  movements,  emotional  in 
origin,  consideration  must  be  given  to  functional  correspondence.  Failure  of 
dissociation  of  associated  movements  as  occurs  following  suture  of  the  spinal 
accessory  to  the  facial,  with  the  facial  musculature  violently  twitching  on  move- 
ments of  the  head  and  shoulders,  etc.,  frequently  extremely  difiicult  to  over- 
come, is  a  drawback  to  nerve  crossing.  These  points  will  be  taken  up  in  greater 
detail  in  connection  with  the  facial  nerve. 


98  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Nerve  Transplantion 

The  first  nerve  graft  in  human  surgery  was  done  by  Albert  (1878)  eight 
years  after  Philipeaux  and  Vulpian  (1870)  had  shown  experimentally  that  a 
segment  of  the  lingual  nerve  interposed  between  two  ends  of  the  hypoglossal 
nerve  was  capable  of  permitting  motor  impulses  to  pass.  Following  removal  of 
a  sarcoma  from  the  median  nerve  Albert  transplanted,  between  the  severed  ends, 
a  nerve  segment  3  cm.  long  taken  from  an  amputated  limb.  In  a  second 
patient  following  excision  of  a  tumor  of  the  ulnar  nerve  with  neurofibromatosis 
10  cm.  was  taken  from  the  posterior  tibial  nerve  and  interposed  between  the 
nerve  ends.  The  transplanted  segment  in  the  latter  case  sloughed,  whereas  in 
the  first  case  primary  union  of  the  wound  took  place.  Unfortunately  no 
further  report  of  this  patient  was  given.  Following  Albert's  cases  of  trans- 
plantation numerous  other  attempts  were  made  with  homotransplants,  auto- 
transplants  and  heterotransplants.  As  heterotransplants  the  sciatic  nerves  of 
the  rabbit,  cat  and  dog  have  been  used,  and  in  one  instance  even  a  segment  of 
the  spinal  cord  of  the  rabbit  (Mayo  Robson,  1890). 

Several  reviews,  including  a  tabulation  of  cases  of  nerve  transplantation 
have  appeared,  notably  those  of  Huber  (1895),  Powers  (1904)  and  Sherren 
(1906).  Attempts  have  been  made  to  draw  deductions  from  cases  reported  in 
these  collections  and  to  compare  results  of  homo-,  auto-  and  heterotransplanta- 
tions, but  unfortunately  this  is  hardly  possible,  since  the  original  reports  do 
not  admit  of  critical  study,  for,  in  many,  the  time  between  the  operation  and 
report  is  too  short  to  allow  of  regeneration,  and  in  others  the  data  given  is 
insufficient  and  the  criteria  accepted  by  the  authors  as  evidence  of  return  of 
function  do  not  warrant  the  conclusion  that  regeneration  took  place.  Albert's 
case  was  lost  sight  of  after  ten  days,  that  of  Atkinson  (1890)  on  the  sixteenth 
day,  those  of  Hoftniann  (1884),  Landerer  (1888),  Kaufmann  (1890),  Maydl 
and  Kukula  (1893),  Heath  (1893)  and  others  before  the  end  of  two  months. 

Of  thirty  cases  included  in  Sherren's  collections  only  nine  were  observed 
one  year  or  longer  and  in  only  two  was  there  any  improvement  which  could  be 
accepted  without  reservation — those  of  Mayo  Robson  (1888)  and  Dean  (1896). 
The  latter  case  is  completely  reported  and  the  criteria  offered  as  evidence  of 
return  indicate  true  sensory  and  motor  regeneration.  In  so  far  as  one  may  con- 
clude from  a  single  case,  successful  nerve  transplantation  is  possible.  Dean 
transplanted  a  segment  of  the  radial  nerve  into  the  musculospiral  to  bridge  a 
defect  of  3  inches.  Movement  began  to  return  in  five  months  and  when  sub- 
sequently examined  by  Sherren,  five  years  after  the  operation,   "(///  muscles 


METHODS  OF  NERVE  REPAIR  99 

supplied  by  the  mitsculospiral  nerve  reacted  in  a  normal  iiuuincr  to  the  interrupted 
current.  Perfect  recovery."  Results  similar  to  those  obtained  in  this  case 
should  be  found  when  the  final  results  of  nerve  transplantation  done  during  the 
past  live  years  are  available.  The  final  results  of  nerve  transplantation  will 
depend,  in  great  measure,  upon  the  most  scrupulous  care  and  precision  in  the 
operative  technic.  In  estimating  the  percentage  of  recoveries  consideration 
must  be  given  to  this  point.  There  are  certain  technical  difficulties  encountered 
in  suturing  nerve  transplants  which  may  account  for  variation  in  the  results 
obtained  by  different  surgeons.  If  the  nerve  grafts  are  not  accurately  sutured, 
and  unless  the  transplanted  segment  lies  end  on  with  its  cross  areas  both 
centrally  and  distally  in  exact  apposition  with  those  of  the  nerve  ends  between 
which  it  is  placed,  the  chances  for  successful  downgrowth  into  the  nerve  seg- 
ment, while  not  precluded,  may  be  greatly  diminished.     (See  Fig.  58.) 

Experimentally  there  can  be  no  doubt  of  the  possibilities  of  this  method  as 
Huber  (1895,  1918),  Nageotte  (1917),  Cajal  (1918)  and  others  have  shown. 
Thus  far  their  results  have  been  substantiated  by  a  few  clinical  cases.  A  com- 
plete tabulation  of  the  recent  cases  of  nerve  transplantation  is  not  feasible  at  this 
time.  However,  there  are  a  few  published  cases  which  indicate  the  probable 
value  in  clinical  surgery  of  this  method  of  bridging  defects.  Swan  (1919) 
reported  a  case  of  ulnar  nerve  injury  in  which  a  gap  of  5^^^  inches  was 
bridged  by  a  single  strand  taken  from  the  radial  nerve.  Return  of  voluntary 
movement  in  the  interosseii  muscles  occurred  and  the  patient  returned  to  com- 
plete active  duty.  In  a  second  a  defect  in  the  posterior  iiaterosseous  nerve  was 
bridged  by  a  single  graft  taken  from  the  radial  nerve.  Complete  return  of 
voluntary  extension  of  the  wrist,  fingers  and  thumb  took  place.  In  one  of  my 
cases  a  defect  of  5  cm.  in  the  lower  third  of  the  arm  was  bridged  with  a  single 
strand  taken  from  the  radial.  A  single  strand  was  used,  since  the  two  nerves  in 
this  position  are  nearly  equal  in  size  and  consequently  the  cross  area  was 
adequately  covered.  Fifteen  months  after  suture  extension  of  the  wrist  and 
fingers  was  possible  but  no  extension  of  the  thumb,  while  twenty-three  months 
after  the  operation  extension  of  the  wrist,  fingers  and  thumb  was  voluntarily 
accomplished,  though  faradic  response  had  not  yet  returned.  Gosset  (1917) 
reported  a  case  of  ulnar  nerve  defect  with  interposition  of  a  single  segment  of 
the  musculocutaneous,  followed  fourteen  months  later  by  some  return  of  ulnar 
sensation.  In  a  case  of  median  nerve  injury  at  the  wrist  a  single  graft  from  the 
musculocutaneous  of  the  leg  was  inserted  and  fourteen  months  later  the  R.D.  in 
the  muscles  of  the  thenar  eminence  had  lessened,  the  muscles  responded  to  the 


lOO         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

faradic  current  and  faradic  cutaneous  sensation  was  perceived  even  on  the  tip  of 
the  index  finger.  In  another  median  nerve  injury  operation  was  done  seventeen 
months  after  the  original  wound  and  a  segment  of  the  internal  cutaneous  nerve 
was  interposed  between  the  nerve  ends.  The  patient  was  much  improved  nine 
months  later,  with  return  of  both  voluntary  and  faradic  contraction.  This  is  a 
remarkable  result  in  view  of  the  interval  between  injury  and  operation  and  the 
rapidity  with  which  regeneration  occurred. 

Joyce  (19 1 9)  reported  seven  cases  of  nerve  grafts,  in  all  of  which  some 
improvement  occurred.     They  are  as  follows: 

1 .  Ulnar  nerve  operated  two  and  a  half  months  after  injury  with  a  defect 
of  2Y1  cm.;  bridged  by  two  strands  taken  from  the  radial.  Twenty-eight 
months  later  partial  motor  and  sensory  return  was  observed. 

2.  Ulnar  nerve  operated  twenty- three  months  after  injury,  with  defect 
of  3.6  cm.;  bridged  by  one  strand  taken  from  the  radial  with  partial  motor  and 
sensory  return  one  year  after  operation. 

3.  Ulnar  nerve  operated  six  months  after  injury,  with  defect  of  3.5  cm.; 
bridged  by  a  single  strand  taken  from  the  radial  nerve.  One  year  later  no 
improvement  was  seen  and  the  nerve  was  re-explored.  "A  large  oval  neuroma 
densely  adherent  to  surrounding  muscles  found  at  upper  end  of  transplant.  This 
bulb  when  liberated  from  the  compressing  scar  tissue  which  surrounded  it  pre- 
sented normal  nerve  tissue  in  size,  shape  and  consistency.  A  smaller  and  similar 
bulb  was  found  at  the  lower  end  of  the  transplant.  Seventy-nine  days  after  this 
liberation  some  sensory  recovery  and  progressive  sensations  of  formication  had 
appeared. 

4.  Ulnar  nerve  operated  ten  months  after  injury,  with  defect  of  12  cm.; 
bridged  by  a  segment  of  the  external  peroneal  nerve.  This  case  was  re-explored 
rather  early,  only  seven  months  after  the  graft  had  been  done.  Here  again 
"a  soft  spindle-shaped  neuromatous  enlargement  was  found  present  at  the 
junction  of  the  upper  segment  with  the  transplant.  A  second  neuroma  of 
similar  size  was  present  at  the  junction  of  the  transplant  with  the  lower  segment. 
No  conduction  of  faradic  current  through  the  transplant.  The  transplant 
was  freed  from  scar  tissue  and  the  wound  closed."  Two  months  after  this 
liberation  progressive  formication  below  the  level  of  the  transplant  was  felt. 

5.  Median  nerve  at  the  wrist  with  interposition  of  a  strand  taken  from  the 
radial  showed  some  return  in  sensation  six  months  later,  as  did  also  a  similar 
case  of  the  posterior  tibial  nerve  at  the  ankle. 

6.  Sciatic  nerve   operated  five  months   after  injury,  with  defect  of  3^^ 


METHODS    OF   NERVE    REPAIR  lOI 

cm.;  bridged  by  three  strands  taken  from  the  radial.  Partial  motor  and 
sensory  recovery  was  reported. 

These  cases  are  of  extreme  importance  since  they  show,  in  a  measure, 
what  can  be  accomphshed  by  nerve  graft  in  human  surgery.  In  the  majority 
of  the  cases  reported,  only  single  strands  were  employed,  whereas  when  the 
diameter  of  the  nerve  permits,  three,  four  or  even  six  strands  forming  a  cable 
graft  should  be  used.  The  aim  should  be  to  approximate,  as  nearly  as  possible, 
the  number  of  funicular  paths  and  offer  a  sufficient  number  of  conducting  tubules 
for  the  neuraxes.  In  many  instances  a  single  strand  may  approximate  in 
diameter  only  one-fifth  the  size  of  the  nerve  trunk  in  which  it  is  placed,  and, 
therefore,  cannot  be  expected  to  carry  anywhere  near  the  same  number  of 
neuraxes  as  the  trunk,  yet  a  relatively  large  proportion  of  the  neuraxes  of  the 
trunk  must  be  transmitted  if  a  good  functional  return  is  to  be  expected. 

Re-exploration  of  a  graft  is  indicated  in  certain  instances,  but  should 
not  be  done  before  growth  to  or  beyond  the  distal  end  of  the  graft  has  had  time  to 
take  place.  In  some  cases  exposure  of  the  graft  and  section  of  the  distal  line  of 
union  with  resuture  may  be  done,  if  it  is  considered  that  further  downgrowth 
of  neuraxes  is  blocked  at  the  distal  line  of  union.  Thus  scar  tissue,  which  may 
have  prevented  further  downgrowth,  may  be  removed  and  regeneration  be 
again  facilitated. 

Among  many  surgeons  a  more  pessimistic  outlook  for  nerve  graft  is  held. 
Piatt  (1920)  reports  eighteen  cases  and  to  his  number  Stopford  (1920)  has 
added  twelve  additional,  in  none  of  which  regeneration  was  found.  These 
authors  condemn  nerve  grafts  since  in  their  cases  no  improvement  was  observed 
up  to  three  years.  It  seems  difficult  to  reconcile  such  total  failures  with  the 
results  of  Sherren  and  Dean,  Swan,  Gosset,  Joyce  and  others,  as  well  as  with  the 
abundant,  brilliant  experimental  evidence  in  support  of  nerve  transplantation. 

A  drawback  to  the  use  of  autogenous  grafts  is  the  additional  time  required 
to  obtain  them  in  an  operation  already  sufficiently  long.  The  time  may  be 
lessened  by  two  operating  teams:  One  to  prepare  the  nerve  ends,  and  the  other 
to  obtain  the  segments  to  be  transplanted.  In  children  autogenous  grafts  are 
rarely  feasible,  since  the  skin  nerves  are  relatively  short  and  small  and  the 
extra  time  required  can  hardly  be  taken  as  in  an  adult. 

Preserved  Grafts. — Huber  (1920)  has  shown  that  grafts  preserved  in 
liquid  paraffin  and  held  in  cold  storage  can  be  used  though  they  are  less  desirable 
than  fresh  grafts.  Dujarier  and  Francois  (1918)  without  any  previous  experi- 
mental work  utilized  this  method  in  twenty  cases.     In  all  but  one  the  wound 


I02         SURGICAL    AND     MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

healed  by  primary  union.  Unfortunately  the  report  was  made  too  early  for 
end  results  to  be  available.  Nageotte  (1918)  recommended  that  nerves 
preserved  in  50/^  alcohol  may  be  used  with  success.  Nageotte  advised 
the  use  of  nerves  taken  from  calves.  Huber  (1920)  repeated  Nageotte's 
experiments  using  homogenous  grafts  and  found  that  regeneration  took  place. 
(See  page  71.)  If  clinical  experience  substantiates  the  experimental  work  in 
the  use  of  preserved  grafts  a  great  advance  will  have  been  made,  in  that  the 
additional  time  required  for  autogenous  grafts  will  be  saved,  and  an  additional 
operation  avoided.  In  Germany,  following  the  recommendations  of  Bethe 
(1916),  nerves  were  obtained  from  fresh  cadavers  and  immediately  used,  or 
preserved  on  ice  for  three  to  seven  days.  Possibly  this  method  of  obtaining 
homogenous  grafts  may  be  satisfactory,  depending  on  the  cause  of  death  and 
the  interval  between  death  and  the  removal  of  the  nerves.  This  method  has 
been  used  by  Steinthal  (1915),  Burk  (1917),  Cahen  (1917)  and  others  without 
infection  or  other  untoward  effects;  however,  no  reports  of  their  end  results 
are  available. 

In  a  large  nerve  it  is  extremely  difficult  to  place  the  required  number  of 
grafts  so  as  to  cover  the  greater  part  of  the  cross  area.  Consequently  a  con- 
siderable number  of  funiculi  will  remain  without  channels  for  downgrowth, 
though  it  is  true  that  neuraxes  may  grow  down  between  the  nerve  transplants. 
Such  a  loss  is  particularly  regrettable  if  the  funicuU  uncovered  happen  to  consist 
of  important  efferent  libers.  Following  loss  of  nerve  substance  with  inter- 
position of  a  cable  graft,  even  under  favorable  circumstances,  a  tremendous 
rearrangement  and  intermingling  of  the  nerve  paths  with  possible  bad  shunt- 
ing is  also  apt  to  occur. 

In  a  few  selected  instances,  depending  both  on  the  size  of  the  nerve  and 
the  funicular  structure,  an  indirect  funicular  suture  may  be  accomplished  and 
the  nerve  graft  interposed  so  that  it  connects  each  end  of  a  funiculus.  Where 
funiculi  can  be  identified  in  both  the  central  and  peripheral  nerve  ends,  as 
being  motor  in  function,  these  should  be  sutured  first,  particular  care  being 
taken  to  insure  the  establishment  of  the  connection. 

Thus  where  individual  technic  may  enter  so  largely  in  the  determina- 
tion of  the  value  of  this  method  of  bridging  nerve  defects  and  where  in  each 
case  the  percentage  of  the  cross  area  covered  by  nerve  grafts  must  also  be  con- 
sidered, marked  variations  in  the  results  are  bound  to  follow.  Unless  these 
facts  are  reckoned  with,  a  method  which  experimentally  has  given  satisfactory 
evidence  of  its  value  mav  be  discounted,  not  because  the  method  itself  is  at 


METHODS  OF  NERVE  REPAIR  IO3 

fault,  but  because  of  insufficient  painstaking  in  technic  and  skill  in  trans- 
plantation. Improvement  in  the  results  of  nerve  grafts  will  be  found  with 
improvement  in  the  technic  of  suture. 

Methods  for  Diminishing  Nerve  Defects 

When  apposition  of  nerve  ends  is  not  possible  in  nerve  defects  there  are 
means  available,  alone  or  in  combination,  to  permit  end-to-end  suture.  These 
methods  are:  free  mobilization  of  the  nerve  ends;  nerve  stretching,  either 
immediate  or  gradual;  transposition  of  the  nerve  to  a  shorter  course;  favor- 
able position  of  the  extremity  and,  in  rare  instances,  shortening  of  the  limb  by 
bone  excision. 

Mobilization  of  the  Nerve. — This  may  be  accomplished  by  wide  exposure, 
dissecting  the  nerve  free  in  its  bed,  both  centrally  and  distally,  and  liberating 
the  branches  which  may  prevent  free  mobilization.  Most  nerve  branches 
may  be  dissected  up  in  the  epineurium  of  the  nerve  trunk  for  quite  a  distance, 
often  to  the  point  at  which  their  funiculi  arise,  since  nerve  branches  generally 
are  formed  higher  in  the  nerve  trunk  than  the  point  at  which  they  leave  it- 
Consequently,  freeing  them  in  their  intraneural  course  may  permit  greater 
mobilization  of  the  main  nerve.  Wide  incisions  are  of  a  further  advantage, 
permitting  indentification  of  the  nerve  both  above  and  below  the  level  of  the 
injury  as  well  as  facilitating  the  mechanics  of  nerve  suture. 

Nerve  Stretching. — Schiiller  (1888)  was  the  first  to  call  attention  to  the 
laxity  of  the  nerve  trunk  and  the  increased  distance  which  might  be  gained  by 
moderate  stretching.  Separated  nerve  ends  may  frequently  be  brought  in 
apposition  by  gentle  traction  and  by  adjusting  the  position  of  the  limb  so  as 
to  relax  the  nerves  and  diminish  the  distance  between  any  two  points  in  the 
course  of  the  nerve.  In  the  nerve  bed  there  is  normally  a  certain  amount  of 
slackness  to  admit  of  free  movement  of  the  extremity  without  tension  upon 
the  nerve  trunk,  which  may  be  taken  up  by  gentle  traction  upon  the  nerve. 
The  greater  amount  of  traction  should  be  applied  to  the  longer  nerve  end, 
preferably  the  distal,  and  sufficient  only  to  take  up  the  normal  laxity  in  the 
contiguous  parts  of  the  nerve  bed.  If  forcible  traction  is  apphed,  the  ventral 
gray  cells  undergo  central  chromatolysis  (see  Fig.  35)  with  consequent  degen- 
eration of  their  peripheral  processes  within  the  central  stump  (Warrington, 
1898).  When  still  greater  force  is  employed  rupture  of  the  funiculi  may  occur 
within  the  nerve  trunk  or  evulsion  of  the  funiculi  from  the  spinal  cord.  The 
blood  supply  of  the  nerve  trunk  may  be  seriously  damaged,  not  in  any  restricted 
portion  but  throughout  the  nerve,  by  rupture  of  the  intraneural  vessels  and 


104        SURGICAL   AND   MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 

the  collateral  blood  vessels  which  enter  the  nerve  from  the  adjacent  tissues. 
The  only  continuity  of  the  nerve  trunk  which  may  remain  intact  is  that  of  the 
connective  tissue  coverings;  these  are  capable  of  greater  extensibility-  It  must, 
of  course,  be  recalled  that  there  is  no  elastic  tissue  in  the  nerve  trunk  and 
stretching  beyond  the  normal  laxity  is  at  the  expense  of  anatomical  continuity. 
Thus,  if  large  defects  be  overcome  by  extensive  stretching,  continuity  only  of 
the  connective  tissue  coverings  is  maintained,  while  grave  damage  is  done  the 
nerve  elements,  not  only  in  the  trunk,  but  even  in  the  ventral  gray  cells. 


Fig.  35. — Rabbit  medulla  five  days  after  evulsion  of  the  left  hypoglossal  nerve.  Xote 
central  chromatolysis  of  motor  cells  of  left  hypoglossal  nucleus  Nissl  stain,  a,  normal  ventral 
gray  cell;  b,  ventral  gray  cell  after  evulsion.     (Collection  of  Oliver  S.  Strong.) 


Stoffel  (191 5)  has  placed  great  emphasis  upon  the  mechanical  relation  of 
the  nerve  to  the  position  of  the  extremity.  The  optimum  position  which  will 
permit  the  nerve  ends  being  brought  together  may  be  determined  at  operation 
by  manipulation  of  the  extremity,  using  flexion,  extension  or  adduction  as  the 
case  may  require.  This  varies  not  only  according  to  the  nerve  injured,  but  also 
with  the  level  of  the  injury.     (See  page  188.) 

When  a  defect  is  too  large  to  be  overcome  by  gentle  stretching  and  altering 
the  position  of  the  limb,  a  two-stage  operation  may  be  undertaken.  In  the 
first  stage  the  nerve  ends  are  freed  but  not  freshened.  The  position  of  the 
limb  is  altered  so  that  the  nerve  ends  may  be  held  in  alignment  by  one  or  two 


METHODS    OF    NERVE    REPAIR  IO5 

silk  sutures  taking  up  as  much  of  the  laxity  of  the  nerve  as  possible.  By  gradu- 
ally lowering  the  limb  during  the  next  few  weeks  the  nerve  is  slowly  stretched. 
Nerve  suture  may  then  be  done.  In  two  patients,  one  with  a  sciatic,  the 
other  a  median  nerve  injury,  the  freshened  nerve  ends  could  not  be  approxi- 
mated, so  the  bulbous  ends  were  sutured  without  excision  of  scar, 
and  the  hmb  put  in  extreme  over  correction,  then  gradually  lowered  until 
straightened.  A  second  operation  was  done  in  the  median  nerve  case,  approxi- 
mately six  weeks  after  the  first  stage.  While  some  lengthening  of  the  nerve 
trunk  had  occurred,  elongation  of  the  connective  tissue  had  taken  place  between 
the  nerve  ends.  On  attempting  to  suture  the  nerve  ends,  normal  appearing 
cross  sections  were  not  obtainable,  even  by  sections  made  at  a  more  remote 
distance  than  is  usually  necessary.  The  cross  section  showed  increase  in  scar 
tissue  with  some  pigmentation.  The  cause  of  this  condition  was  not  fully 
understood  until  the  second  case  was  operated.  Operation  upon  the  second 
patient  was  not  possible  until  three  months  after  the  first-stage  operation  had 
been  done,  due  to  the  fact  that  he  had  absented  himself  from  the  hospital. 
In  this  patient,  at  the  second  operation  the  unfreshened  nerve  ends  were  fairly 
well  united,  though  marked  elongation  of  the  connective  tissue  between  the 
nerve  ends  was  found.  On  section  of  both  the  central  and  distal  segments 
normal  appearing  nerve  ends  such  as  are  usually  found  close  were  not  obtained, 
by  even  remote  sections.  The  funicuH  on  cross  sections  appeared  as  if  strangled 
by  a  marked  increase  of  endoneural  and  perineural  scar — an  appearance  similar 
to  that  found  in  the  distal  portion  of  a  neuroma,  but  the  funiculi  were  separate 
and  small  though  surrounded  by  a  large  amount  of  scar  tissue.  Finally,  when 
as  much  had  been  excised  as  was  deemed  expedient,  without  normal  cross 
sections  being  obtained  the  nerve  trunk  was  palpated  both  centrally  and  distally, 
and  both  the  central  and  distal  ends  were  found  not  compressible  and  markedly 
sclerosed  as  far  as  exposed. 

With  these  findings  we  were  then  able  to  interpret  the  pathological  appear- 
ance of  the  nerve  in  the  first  patient.  In  hoik  intraneural  hemorrhages  had 
occurred;  probably  throughout  a  great  extent  of  the  nerve  trunk,  with  subse- 
quent scar  formation  and  sclerosis.  While  these  two  cases  are  not  conclusive, 
they  would  seem  to  indicate  that  overstretching,  even  when  gradually  applied, 
may  cause  intraneural  liemorrhage  with  subsequent  intraneural  scar  formation. 
The  anatomical  basis  for  such  hemorrhage  is  seen  in  Fig.  77.  This  section  of  a 
typical  nerve,  stained  to  show  the  blood  vessels,  demonstrates  the  rather  exten- 
sive vascular  supply  extending  throughout  the  nerve  trunk  not  only  in  the 


Io6         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

epineurium  but  in  the  perineurium  and  endoneurium,  in  intimate  relation  with 
the  neuraxes.  Thus  any  rupture  of  the  blood  vessels  over  an  extensive  course 
would  cause  serious  endoneural  changes  which  may  destroy  neuraxes  or  block 
their  downgrowth  and  conductivity. 

In  view  of  the  dangers  of  central  chromatolysis  of  the  ventral  gray  cells, 
rupture  of  the  funiculi,  evulsion  of  the  funiculi  from  the  spinal  cord  and  intra- 
neural hemorrhage  with  subsequent  scar  formation,  stretching  must  be  done  ivith 
great  caution.  The  author  holds  that  nerve  stretching  may  be  permitted  only 
up  to  the  point  of  taking  up  the  normal  laxity  of  the  nerve  trunk.  If  greater 
stretching  be  applied,  there  is  danger  of  grave  injury  to  the  nerve,  propor- 
tionately greater  the  greater  the  degree  of  stretching. 

Transposition. — A  nerve  may  be  changed  in  its  course  and  thus  shortened, 
as  when  the  ulnar  nerve  is  passed  in  front  of  the  medial  condyle  of  the  humerus 
or  the  musculospiral  nerve  along  the  medial  surface  of  the  arm.  In  transposi- 
tion the  nerve  branches  must  be  carefully  dissected  up  the  nerve  trunk  to  permit 
freer  mobilization  of  the  nerve.  In  some  instances,  depending  upon  the 
nerve  or  the  branches,  it  may  be  necessary  to  sacrifice  one  or  two  branches  in 
order  to  permit  transposition.  Deliberate  destruction  of  nerve  branches  must 
be  carefully  considered  and  if  done,  with  full  knowledge  of  the  resulting 
paralysis  and  only  after  it  is  determined  that  the  gain  would  more  than  outweigh 
the  additional  loss.  No  set  indications  can  be  given;  each  case  must  be  decided 
individually.  For  example  the  decision  to  sacrifice  the  branches  to  the  flexor 
carpi  ulnaris  and  the  ulnar  half  of  the  flexor  digitorum  profundus  is  justified, 
if  by  so  doing  end-to-end  union  may  be  obtained  and  the  intrinsic  muscles  of  the 
hand  thus  innervated.  The  latter  muscles  are  extremely  important  for  the 
accomplishment  of  the  finer  movements  of  the  hand  and  they  cannot  be  com- 
pensated for  by  tendon  transplantation;  whereas  by  transplantation  of  the  pal- 
maris  longus  into  the  flexor  carpi  ulnaris  and  the  tendons  of  the  flexor  digitorum 
profundus  to  the  fourth  and  fifth  fingers  into  those  of  the  second  and  third,  the 
function  of  these  muscles  may  be  compensated.  Transposition  ot  the  nerve 
does  not  interfere  seriously  with  the  nutrition  nor  the  degree  ot  regeneration. 
In  ulnar  nerve  injuries  Stopford  (1920)  found  that  regeneration  was  more 
complete  with  transposition  than  when  transposition  had  not  been  done.  It  is 
possible  that  with  suture  of  the  nerve  at  the  elbow  without  transposition 
the  line  of  suture  is  subject  to  trauma  on  movements  of  the  elbow  which  in  an 
intact  normal  nerve  would  not  cause  any  injury  but  would  interfere  seriously 
with  regeneration.     While  this  has  not  been  proven,  there  is  sufficient  clinical 


METHODS  OF  NERVE  REPAIR  107 

evidence  to  permit  this  suggestion,  particularly  in  the  ulnar  nerve  and  in  its 
relation  to  old  fractures  ot  the  elbow.  (See  page  369.)  Transposition,  when 
possible,  offers  the  most  favorable  method  of  obtaining  end-to-end  apposition 
in  nerve  defects. 

Resection  of  Bone. — The  cases  in  which  this  procedure  is  justifiable  are 
exetremely  rare.  Due  to  the  grave  compensatory  static  changes  which  would 
follow,  it  is  impossible  to  consider  this  method  to  overcome  nerve  defects  in  the 
lower  extremity.  In  the  upper  extremity  shortening  of  the  humerus  may  be 
justified  when  a  concomittant  fracture  without  union  exists.  This  is  also  true 
in  ununited  fractures  of  the  radius  and  ulna.  Each  case  must  be  considered 
individually  and  resection  done  only  when  it  is  determined  that  other  methods 
are  less  suitable.     It  is  only  in  extremely  rare  instances  that  it  can  be  considered. 

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1863,  pp.  421  and  474. 
Les  Essais  de  greffe  d'un  troncon  de  nerf  lingual  entre  les  deux  bouts  de  I'hypoglosse, 

Arch,  de  physiol.  norm,  et  path.,  v.  3:   1870,  pp.  618-620. 
Platt,   H.:  Results   of   bridging  gaps  in  injured  nerve  trunks  by  autogenous  fascial  tubu- 

lization  and  autogenous  nerve  grafts,  Brit.  J.  Surg.,  v.  7:  no.  27,  Jan.,  1920,  p.  384. 
Powers,  C.  A.:  The  bridging  of  nerve  defects,  Ann.  Surg.,  v.  40:  1904,  p.  632. 
Price,  G.  E.  and  Others:  Nerve  injuries,  Arch.,  Neurol.  &  Psychiat.,  v.  i:  1919,  p.  547. 

Peripheral  nerve  injuries,  J.  Nerv.  &  IMent.  Dis.,  v.  50:   1919,  p.  551. 
Robson,  a.  W.  Mayo:  A  case  of  successful  nerve  grafting,  Clin.  Society  Transactions,  v.  22: 

1888-89,  P-  I20- 
See  Atkinson,  E.:  Remarks  on  nerve  grafting,  Brit.  AL  J.,  v.  2:  1890,  p.  624. 
Case  in  which  the  spinal  cord  of  a  rabbit  was  successfully  used  as  a  graft  in  the  median 

nerve  of  a  man,  Brit.  M.  J.,  v.  2:  Oct.  31,  1896,  p.  1312. 
Schmidt,  J.  E.:  Ueber  Nervenplastik,  Miinch.  med.  Wchnschr.,  v.  64:  1917,  p.  1024. 
Schuller,   M.:  Die  Verwendung  der  Nervendehnung  zur  operativen  Heilung  von  Sub- 

stanzverlusten  an  Nerven,  Wien.  med.  Presse,  Jahrg.  29:   1888,  p.  145. 
Sherren,  J.:  Some  points  in  the  surgery  of  the  peripheral  nerves,  Edinburgh  M.  J.,  v.  20: 

1906,  p.  297. 
Injuries  of  nerves  and  their  treatment,  London,  Nisbet  Co.,  1908. 
Sick,  C.  and  Saenger,  A.:  Heilung  eincr  in  Folge  traumatischen  Defects  bedingten  Liih- 

mung  des  Radialis  durch  Vernahung  des  peripheren  Endes  dieses  Nerven  mit  dem  Med- 

ianus.  Arch.  f.  kUn.  Chir.,  1897,  Bd.  54:  S.  271. 
Smith,  J.  S.  K.  and  Home,  A.  L.:  Nerve  surgery  and  its  results,  J.  Roy.  Army  Med.  Corps., 

V.  S3-  191Q.  P-  485. 


METHODS  OF  NERVE  REPAIR  III 

SouTTAR,  H.   S.:  Injuries  of  the  peripheral  nerves   from  the  surgical  standpoint,  Brit.  J. 

Surg.,  V.  6:   1918,  p.  279. 
Spear,  I.  J.  and    Babcock,    W.    W.:  Peripheral  nerve  injuries  concomitant  to  gunshot 

wounds,  Arch.,  Neurol.  &  Psychiat.,  v.  2:   1919,  p.  253. 
Spitzy,  H.:  Die  Bedeutung  der  Nervenplastik  fiir  die  Orthopadie.,  Ztschr.  f.  orthop.  Chir., 

V.  13:   1904,  p.  ,526. 
Bemerkungen  zur  Ueberbrtickung  von  Nervendefekten,   Mijnchen.  med.  Wchnschr.,  v. 

64:  Marz  1917,  p.  372. 
SxElNTH.iiL,:  Die    Deckung    grosserer    Nervendefckte    durch    Tubularnaht,    Bruns'    Beitr. 

z.  klin.  Chir.,  v.  96:   1915,  p.  295. 
Ueber  scheinbare  Heilungen  nach  Nervennahten,  Med.  Correspondenzbl.  d.  Wurttemb. 

Aerztl.  Landesver,  v.  87:  1917,  p.  iig;  Beitr.  z.  klin.  Chir.,  v.  107:   1917,  p.   576. 
Stiles,  N.  J.:  Operative  treatment  of  nerve  injuries.  Am.  J.  Orlhop.  Surg.,  v.    16;  1918, 

P-  351- 
Stoffel,  A:  Ueber  die  Behandlung  Verletzter  Nerven  im  Kriege,  JMiinchenmed.  Wchnschr., 

V.  62:  1915,  p.  201. 
Ueber  Nervenmechanik  und  ihre  Bedeutung  fur  die  Behandlung  der  Nervenverletzungen, 

MUnch.  med.  Wchnschr.,  v.  62:   1915,  p.  889. 
Stookey,    B.:  The    futility   of   bridging   nerve  defects  by    means   of   nerve   flaps,    Surg., 

Gynec.  &  Obst.,  v.  29:  Sept.,  1919,  p.  287. 
Stopford,   J.    S.   B.:  The   results   of    secondary    suture    of    peripheral   nerves.  Brain,    v. 

43:  pt.  I,  1920,  p.  I. 
The  treatment  of  large  defects  in  peripheral  injuries,  Lancet,  v.  2:  Dec.  25,  1920,  p.  1296. 
Swan,  R.  H.  J.:  Surgical  treatment  of  peripheral  nerve  injury  and  its  results,  Arch.  Radiol. 

&  Electroth.,  v.  23:  1918-1919,  p.  62. 
TiLLMANNs:  Ueber  die  Operativ-Behandlung  von  Substanzverlusten  an  peripheren  Nerven, 

Verhandl.  d.  deutsch.  Gesellsch.  f.  Chir.,  v.  14:  Congress,  1885,  p.  213. 
\'uLPius,    O.  and    Stoffel,    A.:  Orthopadische   Operationslehre,    Stuttgart,    Verlag   von 

Ferdinand  Enke,  2  vols.  1911-1913., 
Walther,  M.:  Manifestation  rapidede  regeneration  du  nerf  median  apresgreffede  Nageotte, 

Soc.  de  Chir.  Bull.  &  Mem.,  v.  46:   1920,  p.  300. 
Warrington,  W.  B.:  On  the  structural  alterations  observed  in  nerve  cells,  J.  Physiol., 

v.  23:  1898,  p.  112. 


CHAPTER  IV 
DIRECT  NERVE  IMPLANTATION  AND  DIRECT  MUSCLE  IMPLANTATION 

DIRECT  NERVE  IMPLANTATION 

Both  experimental  and  clinical  evidence  show  that  if  the  central  end  of  a 
motor  nerve  be  implanted  into  a  muscle  whose  nerve  has  been  cut  it  will  form 
motor  end  plates  and  re-establish  motor  function.  Practically,  this  method 
only  can  be  used  in  those  rare  instances  in  which  a  motor  nerve  can  be  devoted 
to  the  exclusive  supply  of  one  muscle,  or  when  branches  sufl&ciently  large  to 
offer  an  adequate  nerve  supply  are  available.  It  is  here  that  its  greatest  held 
of  usefulness  will  be  found,  particularly  where  muscle  branches  destroyed  near 
their  entrance  into  the  muscle  may  be  freed  and  implanted  into  the  muscle  at 
a  higher  level. 

Clinically,  Hacker  (1908)  was  the  first  to  try  direct  nerve  implantation,  and 
claims  to  have  obtained  functional  return.  The  operation  was  done  on  a  girl 
twenty-four  years  old,  with  paralysis  of  the  trapezius  muscle  following  injury  to 
the  spinal  accessory  nerve  during  an  operation  for  glands  of  the  neck.  Hacker 
implanted  the  central  end  of  the  spinal  accessory  into  the  trapezius  and  also  a 
motor  branch  from  the  cervical  plexus.  He  also  implanted  a  flap  of  muscle  from 
the  levator  scapulae  and,  at  a  second  operation  a  year  later,  implanted  an 
additional  muscular  flap  from  the  deltoid  muscle.  Electrical  stimulation  of  the 
deltoid  and  levator  scapulse  subsequently  caused  partial  contraction  of  the 
trapezius,  and  stimulation  of  the  spinal  accessory  nerve  and  the  cer\ical  plexus 
at  the  point  of  implantation  with  the  trapezius  caused  contraction  of  part  of  this 
muscle.  It  was  noted  that  contraction  took  place  more  forcibly  in  the  immediate 
vicinity  of  the  site  of  both  muscular  implantations.  Kolliker  (191 7)  reported 
two  cases  of  motor  return  in  the  biceps  muscle,  in  which  six  months  previously 
he  had  implanted  the  entire  end  of  the  median  nerve. 

Forrester  (1918)  performed  direct  nerve  implantation  of  the  mechan, 
musculocutaneous,  and  peroneal  nerves  with  complete  return  of  function  in 
four,  partial  in  one,  and  complete  failure  in  one.  Lehrmann  (1918)  found  no 
motor  return  thirteen  months  after  implantation  of  the  musculospiral  into  the 
supinator  longus,  or  twenty-three  months  after  implantation  of  the  spinal 
accessory  into  the  trapezius. 


DIRECT    NERVE    IMPLANTATION    AND    DIRECT    MUSCLE    IMPLANTATION       II3 

Experimentally,  Erlacher  (1914)  implanted  the  median  nerve  into  the 
biceps  of  a  monkey  after  having  severed  the  musculocutaneous  nerve.  Twenty- 
eight  days  later  contraction  of  the  biceps  was  obtained  on  stimulation  of  the 
median  nerve,  using  the  same  strength  current  as  was  required  to  obtain  motor 
response  in  other  nerves  of  the  same  animal.  Histological  examination 
(Bielschowsky's  method)  of  the  biceps  showed  normal-appearing  nerve  hbers 
throughout  the  muscle  (see  Figs.  36  and  37),  thus  both  histologically  and  physio- 


Fig.  36.  Fig.  37. 

Fig.  36. — Direct    implantation.     Very    delicate    reddish-brown    impregnated    end    plate   of   the 

implanted   ulnar  nerve.     Very  few  nuclei.     (Erlacher,  Zeitschr.  f.  Orthop.  Chirurg.,  1914.) 
Fig.  37. — Direct  implantation.     Newly  formed  end  plate  of  the  ulnar  nerve  with  distinct  sole  plate 
anlage.     (Erlacher,  Zeitschr.  f.  Orthop.  Chirurg.,  1914.) 

logically  demonstrating  the  'establishment  of  neuromuscular  connections. 
Heinike  (1914)  and  his  pupils,  Haberland  and  Miller,  obtained  neurotization  of 
the  gastrocnemius  of  the  rabbit,  after  severance  of  the  tibial  portion  of  the  sciatic 
by  direct  implantation  of  the  peroneal  nerve.  Regeneration  occurred  within 
twenty-eight  days,  and  at  the  end  of  lifty-six  days  the  gastrocnemius  showed 
normal  contraction  on  stimulation  as  well  as  contraction  of  the  neighboring 
flexor  group  previously  paralyzed.  This  latter  fact  Heineke  has  made  no 
attempt  to  explain.  It  is  difficult  to  conceive  of  a  nerve  implanted  into  one 
muscle  reaching  adjacent  muscles  when  these  muscles,  normally,  not  only  are 
not  in  direct  connection,  but  are  separated  from  each  other  by  intermuscular 
spaces.  It  is  not  possible  to  accept  these  results  until  they  have  received  further 
confirmation. 


114         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Steindler  (1916),  following  the  work  of  Heinike  and  Erlacher,  obtained 
active  contraction  of  the  vastus  externus  in  two  or  three  of  his  animals  on  stimu- 
lation of  the  implanted  nerve.  The  contraction  was  greatest  nearest  the  point  of 
implantation,  and  in  one  experiment,  examined  early,  contraction  of  the 
distal  part  gave  slow  undulating  waves  instead  of  a  rapid  sharp  response.  Such 
a  response  was  also  reported  by  Gerster  and  Cunningham  (191 7)  and  is  similar 
to  that  found  clinically  by  Hacker  in  which  contraction  was  greatest  nearest  the 
site  of  implantation. 


Fig.  38. — Muscle  curves  obtained  from  stimulation  of  a  foreign  nerve  implanted  directly  into  a 
muscle.     (Ulnar  nerve  implanted  into  the  biceps  in  a  rabbit.) 

Hoessly  (1916)  implanted  the  motor  branch  of  the  spinal  accessory  nerve 
to  the  sterno-cleido-mastoid  into  the  muscles  of  the  larynx  on  the  right  side,  in 
three  dogs,  after  having  excised  6  cm.  from  the  right  recurrent  laryngeal 
nerve.  Examination  of  the  vocal  cord  following  the  operation  showed  the  right 
cord  to  be  in  the  cadaveric  position.  Examination  live  months  later  showed 
the  position  of  the  vocal  cord  very  much  improved  in  two  of  the  dogs  and  they 
were  no  longer  hoarse.  The  third  dog  showed  no  improvement.  Hoessly 
obtained  neurotization  of  the  larynx  adductors  so  that  the  vocal  cord  could  be 
brought  to  the  midline,  and  histological  studies  (Bielschowsky's  method) 
showed  numerous  nerve  fibers,  motor  end  plates  and  normal  muscle  tissue. 
As  the  result  of  these  experiments  he  suggested  the  possibility  of  a  similar 
operation  in  selected  cases  in  the  human,  and  presented  a  theoretical  operative 
technic.     (See  page  420.) 

Elsberg  (1917)  working  on  rabbits,  found  that  in  eight  to  ten  weeks 
"paralyzed  muscle  tissue  regularly  regenerates  under  the  influence  of  the 
regenerating  (implanted)  motor  nerves,"  and  that  of  two  nerves  implanted 
one  the  severed  nerve  of  the  muscle,  the  other  a  foreign  nerve,  the  normal  nerve 
to  the  muscle  establishes  motor  connections,  while  the  foreign  nerve  does  not 


DIRECT    NERVE    IMPLANTATION    AND    DIRECT    MUSCLE    IMPLANTATION       II  : 


Erlacher  (1914)  implanted  the  ulnar  nerve  eight  times  and  the  median  nerve 
twice  in  a  normal  biceps  having  its  normal  nerve  supply.  In  each  instance  he 
obtained  neuromotor  connections,  so  that  stimulation,  using  the  same  minimum 
current,  of  either  the  musculocutaneous  or  the  implanted  nerve  gave  identical 
motor  responses.  He  concluded  that  the  additional  implantation  of  a  motor 
nerve  had  increased  the  nerve  supply  to  the  muscle  which  he  termed  hyper- 


IN.    M.N. 


N.Mi. 


IV 
Fig.    39. — Hyper  neurotization 
of   a   muscle  having   normal    nerve 
supply.     (Erlacher,  P.   Amer.   Jour. 
Orthop.  Surg.,  1915.) 


m 

Fig.  40. — Muscular  neurotization 
of  a  paralyzed  muscle.  (Erlacher. 
P.  Amer.  Jour.  Orthop.  Surg.,  1915.) 


iicurolizalion.  (See  Fig.  39.)  Histological  studies  in  serial  sections  of  the 
biceps  muscle  showed  young  growing  neuraxes  from  the  implanted  nerve,  which 
he  was  able  to  trace  as  far  as  the  formation  of  young  motor  end  plates. 
"The  microscopical  examination  demonstrated  that  the  musculocutaneous 
nerve  showed  its  normal  distribution  in  the  muscle  and  the  presence  of  normal 
motor  end  plates.  While  in  the  vicinity  of  the  implanted  nerve,  and 
adjacent  to  thick,  deeply  impregnated,  black,  myelinated  nerve  fibers, 
small,  fine  and  reddish-brown  nerve  fiber  of  either  the  ulnar  or  median 
developed,  and  on  apparently  perfectly  normal  muscle  fibers,  delicate  end 
plates  were  formed  as  are  usually  seen  from  motor  nerves."  These  newly 
formefl  "end  plates"  were  readily  distinguishable  from  the  normal  end  plates 


Il6         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

of  the  normal  nerves.  The  investigations  of  Steindler  (1916)  and  others  are 
in  direct  contradiction  and  led  them  to  conclude  that  hypcrncurotization  of 
normal  muscle  is  impossible.  However,  the  presence  of  two  or  more  motor  end 
plates  on  a  single  muscle  liber  cannot  be  taken  to  indicate  hyperneurotization, 
since   it   is  well  known  that  a  single  muscle  fiber  may  possess  two  or  three 


Fig.  41.  Fig.  42. 

Figs.  41  and  42. — Direct  nerve  implantation.  Two  fine  waxed  silk  sutures,  A  and  B,  are 
passed  through  the  epineurium  about  2  mm.  from  the  nerve  ends  at  opposite  points.  The  muscle  is 
then  slit  and  after  a  moment's  wait  for  hemostasis,  the  nerve  is  implanted.  Both  ends  of  A  and 
B  are  passed  in  the  muscle  as  mattress  sutures  and  tied.  The  slit  in  the  muscle  is  then  sutured  and 
two  additional  epineural  sutures,  C  and  D,  hold  the  nerve  tn  prevent  sharp  angulation  at  the  point 
of  implantation. 

! 

motor  end  plates.  Agduhr  (1919)  studied  degeneration  of  nerve  endings  in  the  ! 
flexor  digitorum  sublimis  muscle  after  cutting,  at  different  intervals,  the  sev- 
enth and  first  thoracic  roots,  leaving  the  eighth  cervical  intact,  and  in  this 
manner  found  that  the  individual  muscle  fiber  may  have  two  or  three  motor  j 
end  plates  as  shown  by  the  presence  of  motor  plates  in  ditferent 
degenerative  phases.  In  regeneration  of  previously  denervated  muscle 
Boeke  (1916)  found  more  than  one  nerve  ending  on  individual  nerve 
fibers.  Complete  neurotization  of  muscle  by  direct  nerve  implanation 
is  influenced  also  by  the  anatomy  of  the  muscle.     In  such  muscles  as  the      j 


DIRECT    NERVK    IMPLANTATION    AND    DIRECT    MUSCLE    IMPLANTATION        II 7 

trapezius,  serratus  anterior,  subscapularis,  etc.,  made  up  of  fibers  running  in 
different  directions  or  having  digitations  each  more  or  less  separate  except  near 
the  insertion,  innervation  occurs  in  the  digitation  into  which  the  nerve  is 
implanted  and  is  not  apt  to  extend  to  adjacent  digitations  or  to  include  the 
whole  muscle.  Implantation  is  most  successful  in  muscles  whose  fibers  run  a 
parallel  course  and  whose  normal  innervation  is  from  a  nerve  which  supplies  the 
muscle  by  breaking  up  into  terminal  branches  within  the  muscle,  rather  than 
in  muscles  whose  fibers  are  arranged  in  digitations  and  whose  nerve  supply  is  by 
separate  branches  to  each  digitation. 

Technic  of  Nerve  Implantation. — The  central  end  of  the  nerve  to  be 
implanted  is  freshened  to  a  scar-free  area  and  normal-appearing  funiculi. 
Two  fine  epineural  sutures  are  passed  at  opposite  points  2  mm.  from  the 
nerve  end.  The  point  in  the  muscle  at  which  the  nerve  is  to  be  implanted  is 
selected,  bearing  in  mind  the  movement  of  the  muscle  during  contraction  and 
during  changes  in  position  of  the  extremity,  selecting  a  point  so  that  there  will 
be  no  tension  on  the  nerve.  A  slit  is  then  made  in  the  muscle  in  the  direction 
of  the  muscle  fibers.  A  small,  moist,  warm  cotton  pad  is  placed  in  the  opening 
of  the  muscle  and  over  the  nerve  end  and  a  moment  waited  for  complete  hemo- 
stasis.  Both  ends  of  the  epineural  sutures  are  passed  in  the  muscle  as  mattress 
sutures.  These  are  placed  so  as  to  direct  the  nerve  end  downward  in  the  direc- 
tion of  the  muscle  fibers.  The  opening  in  the  muscle  is  then  closed  and  two 
additional  epineural  sutures  are  passed  to  hold  the  nerve  in  place  and  prevent 
angulation  of  the  nerve  at  the  point  of  suture.     (See  Figs.  41  and  42.) 

DIRECT  MUSCLE  IMPLANTATION 

Neurotization  of  paralyzed  muscle  through  nerve  fibers  contained  in  a 
transplanted  muscle  flap,  by  direct  outgrowth  of  the  neuraxes  from  the 
flap  into  the  paralyzed  muscle,  offers  a  seductive  method  of  re-establishment 
of  motor  innervation.  If  proven  successful,  the  opportunities  for  clinical  appli- 
cation of  such  a  method,  contrary  to  direct  nerve  implantation,  would  be  legion. 

The  method  was  first  tried  by  Gersuny  (1906)  when  he  implanted  a  part 
of  the  trapezius  into  the  paralyzed  deltoid  and  claimed  to  have  obtained  a 
functional  result.  Hacker  transplanted  a  part  of  the  levator  scapulae  into  the 
paralyzed  trapezius  with  functional  return.  However,  at  the  same  time  the 
spinal  accessory  nerve  was  implanted  directly  into  the  muscle,  so  that  it 
is  difficult,  in  this  case,  to  determine  the  source  of  the  regenerating  neuraxes, 
though  Hacker's  electrical  stimulation  might  support  the  view  that  outgrowth 


Il8         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

had  taken  place  from  both  sources.  Erkrcher  (1Q14)  attempted  muscle  im- 
plantation, experimentally,  in  guinea  pigs,  in  which  he  transplanted  slips  of 
the  deltoid  or  pectoralis  major  into  a  previously  paralyzed  biceps.  (See  Fig.  40. ) 
He  reports  that  neurotization  of  the  biceps  was  obtained,  as  demonstrated  by 
physiological  stimulation  of  the  biceps  and  by  microscopical  studies  of  the 
biceps.  Normal  motor  end  plates  were  found  with  a  distinct  neurofibular 
outgrowth  from  the  neuraxes  of  the  implanted  muscle  flap,  and  complete 
regeneration  of  the  muscle  fibers  of  the  biceps.  At  first,  on  stimulation, 
simultaneous  contraction  of  both  muscles  followed,  that  is,  stimulation  of  the 
deltoid  caused  contraction  of  the  deltoid  and  the  biceps,  but  in  later  stages 
isolated  contraction  of  either  muscle  could  be  produced.  Such  dissociation  in 
function  is  indeed  remarkable,  and  calls  for  further  substantiation. 

Erlacher  advises  that  the  implanted  muscle  flap  have  a  broad  base,  so  as  to 
insure  its  nerve  supply.  The  flap  retains  its  power  of  contraction  and  at  once 
begins  to  send  outgrowths  of  neuraxes  into  the  adjacent  muscle  tissue  in  which, 
later,  normal  motor  end  plates  may  be  found.  "After  forty-eight  days,  electri- 
cal stimulation  of  the  implanted  flap  caused  contraction  of  the  biceps,  and  in 
microscopical  preparation  I  found  nerve  fibers  from  the  muscle  flap  growing 
through  the  line  of  scar  tissue  uniting  the  muscle  flaps,  into  the  paralyzed 
biceps,  and  there  forming  young  regenerating  end  plates." 

Erlacher  says,  "muscular  neurotization  may  be  obtained  in  three  different 
ways:  First,  we  may  remove  the  connective-tissue  sheath  from  two  muscles 
running  side  by  side  and  sew  them  together;  this  method  is  to  be  recommended 
only  in  the  case  of  muscles  with  identical  action,  such  as  the  tibialis  anticus, 
extensor  hallucis,  and  extensor  digitorum  or  the  extensor  digitorum  and  peroneus 
Second,  we  may  form  a  long,  centrally  pedunculated  flap  from  the  healthy 
muscle,  freshen  it  widely  and  graft  it  into  the  paralyzed  muscle;  in  this  way  we 
can  bridge  intervening  spaces.  This  method  is  available  for  the  neurotization 
uf  the  tibialis  or  the  peronei  from  the  gastrocnemius,  from  the  cjuadriceps  to  the 
flexors  of  the  leg,  or  from  the  brachial  triceps  to  the  biceps.  Third,  we  may 
sacrifice  a  whole  muscle  by  cutting  it  at  its  tenchnous  insertion  and  either  stitch 
it  well  freshened  into  the  paralyzed  muscle  (for  example,  the  flexors  of  the  leg, 
or  the  tensor  fascia;  femoris  or  sartorius  into  the  quadriceps),  or  we  may  make 
an  end-to-end  connection  with  the  paralyzed  muscle  (as,  for  instance,  the  tra- 
pezius into  the  deltoid)." 

In  one  patient  reported  by  Erlacher,  in  whom  part  of  the  peroneus  muscle 
was  sutured  into  the  tibialis  posticus,  contraction  of  the  tibialis  posticus  followed 


DIRECT    NERVE    IMPLANTATION    AND    DIRECT    MUSCLE    IMPLANTATION       II Q 

electrical  stimulation  of  either  the  peroneal  flap  or  the  tibialis  posticus  muscle. 
However,  no  movement  of  the  foot  took  place  and  only  a  slight  tension  of  the 
tendon  was  seen.  Two  other  patients  are  recorded,  one  in  whom  there  was 
paralysis  of  the  biceps  and  in  the  other  paralysis  of  the  deltoid.  In  each, 
muscle  implantation  was  performed,  but  unfortunately  the  cases  were  reported 
before  end  results  were  possible,  and  consequently  they  offer  no  light  on  the 
clinical  application  of  this  form  of  neurotization. 

Of  twenty  muscle  implantations  done  by  Nutt  (191 7)  in  cases  of  infantile 
paralysis  thirteen  were  functionally  failures,  while  four  showed  fair  recovery, 
and  two  good  recovery.  In  this  connection  it  must  be  recalled  that  in  paralysis 
of  anterior  poliomyelitis  adequate  mechanical  treatment  such  as  is  given,  for 
example,  after  tendon  transplantation,  may  in  itself  allow  return  of  function. 
Sir  Robert  Jones  has  held  it  as  a  cardinal  principle,  which  my  own  experience  has 
confirmed,  that  in  paralysis  of  anterior  poliomyelitis  no  operation  such  as  tendon 
transplantation  or  reinnervation  should  be  performed  until  the  latent  power  of 
returning  function  shall  have  been  given  an  opportunity  for  re-establishment  by 
complete  rest  for  at  least  six  months.  Consequently  it  is  suggested  that  before 
the  return  of  function  in  anterior  poliomyelitis  can  be  attributed  to  neu- 
rotization by  direct  muscle  implantation,  these  muscles  should  be  placed  in 
absolute  rest  sufficiently  long  to  exhaust  the  possibility  of  their  own  unaided 
restitution. 

Though  very  alluring,  direct  muscle  neurotization  by  muscle  implantation 
needs  further  confirmation  both  clinically  and  experimentally,  particularly  the 
early  dissociation  in  function,  and  early  isolated  contraction  of  the  neurotized 
muscle  reported  by  Erlacher  in  his  experimental  work. 


REFERENCES 

Agduhr,  E.:  Morphologischer  Beweis  der  doppelten  (pleurisegmentalen)  motorischen 
Innervation  der  einzelen  quergestreiften  Muskelfasern  bei  den  Saugetieren,  Anat. 
Anz.,  1916,  49,  1-13. 

Agduhr:  Sympathetic  innervation  of  the  muscles  of  the  extremities,  a  histo-experimental 
study,  Verhr.  d.  K.  Akad.  v.  Wetensch.,  Amsterdam,  iqig. 

BoEKE,  J.:  Die  doppelte  motorische  und  sympathetische  effcrcnte  Innervation  der  quer- 
gestreiften Muskelfasern,  Anat.  Anzeiger,  1913,  44,  343. 
Studien  zur  Kervenrcgencration  I,  \'erh.  d.  K.  .\kad.  v.  Wetensch.,  .\msterdam,  iqi6, 

18,  91. 
Studien  zur  Xervenregeneratiun  II.  X'erli.  d.  K.  .\kad.  v.  Wetensch.,  .\nisterdam,  igi;,  19. 


I20  SITRGICAL    AND    MECHANICAL    TREATMENT    OF    PERPHERAL    NERVES 

Elsberg,  C.  a.:  Experiments  on  motor  nerve  regeneration  and  the  direct  neurotization  of 

paralyzed  muscles  by  their  own  and  by  foreign  nerves,  Science  (N.  S.),  v.  45:  (Mar.  30), 

1917,  p.  319. 
Erlacher,  p.:  Hyperneurotisation;  muskulare  Neurotisation;  freie  Muskeltransplantation. 

Experimentelle  Untersuchungen,  Zentralbl.  f.  Chir.,  April,  1914,  v.  41:  no.  15,  p.  625. 
Erlacher,    P.:  Ueber    die   motorischen   Nervenendigungen.     Histologische   und   experi- 
mentelle Beitrage  zu  den  Operationen  an  den  peripheren  Nerven,  Ztschr.  f.   orthop. 

Chir.,  V.  34:  1914,  p.  561. 
Erlacher,   P.:  Direct   and   muscular   neurotization   of  paralyzed  muscles.   Experimental 

research.  Am.  J.  Orthop.  Surg.,  v.  13;  July,  1915,  pp.  22-32. 
Foerster,  O.:  Die  Symptomatologie  und  Therapie  der  Kriegsverletzungen  der  peripheren 

Nerven,  Deutsch.  Ztschr.  f.  Nervenh.,  v.  59:  1918,  p.  32. 
Gerster,  J.J.  C.  and  Cunningham,  W.  F.  :  Neurotization  of  paralyzed  muscles  by  implanta- 
tion of  motor  nerves,  Med.  Record,  v.  92:  August,  191 7,  p.  223. 
Gersuny,  R.:  Eine  Operation  bei  motorischen  Lahmungen,  Wien.  klin.  Wchnschr.,  v.  19: 

1906,  p.  263. 
Hacker,  v.:  Erfolgreich  operativ  behandelte  Cucullarislahmung,   Wien.   klin.   Wchnschr., 

V.  21:  2,  1908,  p.  1314  (no.  37). 
Hacker,  v.:  Direkte  Nerveneinpflanzung  in  den  Muskel  und  muskulare  Neurotisation  bei 

einem  Falle  von  Cucullarislahmung,  Zentralbl.  f.  Chir.,  v.  41:  i,   1914,  p.  882. 
Heineke:  Die  direkte  Eintlanzung  des  Nerven  in  den  INIuskel,  Zentralbl.  f.  Chir.,  no.  11, 

V.  41:  1914,  p.  465. 
HoESSLY,   H.:  Ueber  Nervenimplantation  bei  Recurrenslahmungen,     Eine  experimentelle 

Studie,  Beitr.  z.  klin.  Chir.,  v.  99:   1916,  p.  186. 
KoLLiKER,:  Einpflanzung  eines  Astes  des  Nervus  medianus  in  den  Musculus  biceps  nach 

Heineke,  Zentralbl.  f.  Chir.,  1917,  p.  21. 
NuTT,  J.  J.:    Neurotization  of   paralyzed  muscle  by  muscle  grafting,  J.  A.  M.  A.,  v.  69: 

Dec.  22,  1917,  pp.  2082-2085. 
Steindler,  A.:    Direct  neurotization  of  paralyzed  muscles;  further  study  of  the  question  of 

direct  nerve  implantation,  Am.  J.  Orthop.  Surg.,  v.  14:  1916,  p.  707. 
Steindler,  A.:  Method  of  direct  neurotization  of  paralyzed  muscles.  Am.  J.  Orthop. Surg. 

V.  13:  July,  191S,  pp.  33-45- 


CHAPTER  V 
TUBULIZATION 

In  addition  to  the  various  other  methods  of  nerve  repair  tubuHzation 
has  been  employed  to  bridge  nerve  defects  either  in  conjuction  with  other 
methods  or  by  itself.  By  tubuHzation  is  meant  the  using  of  tubes  of  decal- 
cified bone,  hardened  arteries,  fresh  veins,  agar,  gelatine,  fascia  lata  or  car 
gile  membrane,  etc.,  as  a  channel  through  which  the  neuraxes  may  be  directed 
toward  the  distal  nerve  end.  Thus  the  danger  of  neuraxes  being  cut  off  by 
ingrowth  of  scar  between  the  nerve  ends  is  minimized  and  the  loss  of  nerve 
fibers  by  dispersion  into  the  surrounding  tissues  lessened.  TubuHzation  offers 
a  single  large  path  for  the  downgrowth  of  neuraxes  and,  for  this  reason,  is 
mechanically  inferior  to  nerve  transplantation  for  nerve  regeneration,  since 
the  latter  method  offers  numerous  small  paths  which  serve  as  individual  con- 
ducting tubules  for  the  neuraxes.  The  numerous  small  conduits  of  the  nerve 
graft  direct  the  neuraxes  along  a  straight  path  within  which  they  rarely  meet 
with  resistance;  whereas,  the  relatively  large  tube  in  an  arterial  or  fascial 
tubuHzation  may  collapse,  or  be  invaded  by  connective  tissue  and  thus  block 
the  neuraxes.  Evidence  of  the  resistance  which  such  scar  tissue  offers  within 
the  lumen  of  the  tube  is  seen  by  the  tortuous  course  of  the  neuraxes  and  their 
criss-cross  direction,  becoming  more  marked  the  farther  the  downgrowth 
from  the  central  stump  and  the  denser  and  older  the  scar  tissue.  Nerve  trans- 
plantation may  be  considered  individual  or  neuraxis  tubuHzation  as  contrasted 
with  gross  or  nerve  trunk  tubuHzation. 

Tubular  coverings  have  also  been  used  to  isolate  and  protect  the  nerve 
trunk  from  scar  tissue  following  end-to-end  suture,  with  the  intention  of  form- 
ing a  scar-free  bed  for  the  nerve.     Unfortunately  not  all  tubular  methods 
accomplish  the  end  for  which  they  are  intended,  either  as  a  conducting  path 
or  as  a  means  of  nerve  trunk  isolation. 

Decalcified  Bone  TubuHzation. — The  first  attempt  at  tubuHzation 
was  hardly  more  encouraging  than  later  clinical  and  experimental  efforts. 
Gliick  (1881)  inserted  an  Eschmarch-Neuber  decalcified  bone  drain  between 
the  severed  ends  of  a  sciatic  nerve  and  found  that  only  connective  tissue 
continuity  was  established,  with  no  functional  return.     Vanlair  (1885)  repeated 


122  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

this  experiment  using  similar  decalcified  bone  tubes  and  found  that  down- 
growth  of  nerve  fibers  occurred,  with  some  of  the  neuraxes  reaching  as  far  as 
the  distal  segment;  but  Vanlair's  results  have  not  been  sufiiciently  corroborated. 
Huber  (1895)  performed  eight  similar  experiments,  five  of  which  were  observed 
more  than  fifty  days,  and  in  only  one  of  these  was  there  any  functional  regen- 
eration. At  the  end  of  a  hundred  and  fifty-five  days  the  downgrowth  had 
extended  as  far  as  the  middle  of  the  forearm,  while  in  the  remaining  experi- 
ments no  functional  return  occurred,  though  a  few  neuraxes  were  found  in  the 
upper  part  of  the  distal  stump.  Examination  of  the  tubilization  showed  that 
the  neuraxes  were  more  regularly  arranged  nearest  the  central  stump  and  that 
as  the  distal  stump  was  approached  the  nerve  bundles  became  fewer  and  more 
tortuous.  This  Huber  thought  was  due  to  the  "fact  that  at  a  time  when  the 
neuraxes  are  beginning  to  grow  toward  the  periphery,  the  less  developed  con- 
nective tissue,  just  below  the  central  stump,  offers  less  resistance  to  them  than 
does  the  same  tissue  at  a  later  stage,  it  having  obtained  a  denser  and  more 
highly  organized  structure. " 

Decalcified  bone  tubes  are  relatively  quickly  absorbed,  in  many  instances 
remain  less  than  three  weeks  in  the  tissues.  Neuber  himself  dwelt  at  length 
on  their  absorbability,  while  Vanlair  claimed  they  remained  about  four  months. 
Ruber's  results  also  support  the  experience  of  Neuber  that  they  are  readily 
absorbed.  The  tubes  are  replaced  by  connective  tissue,  more  or  less  similar 
in  arrangement  to  that  which  replaces  the  catgut  bundles  in  suture  a  distance, 
where  the  scar  tissue  is  said  to  oft'er  less  resistance  to  the  downgrowing  neuraxes 
than  the  surrounding  denser  fibrous  tissue. 

Arterial  Tubulization. — Following  the  experiments  of  Gliick  and  Vanlair 
Biingner  (1891)  successfully  bridged  a  small  distance  between  the  retracted 
ends  of  a  severed  sciatic  nerve  by  means  of  tubulization,  using  a  segment  of 
sterilized  human  brachial  artery.  In  this  case  the  nerve  was  merely  severed 
and  there  was  no  loss  of  substance.  Such  a  regeneration  as  Biingner  reported 
over  the  distance  between  nerve  ends  merely  retracted,  without  real  defect, 
we  now  know  is  possible  by  unaided  downgrowth,  without  the  assistance  of  any 
form  of  tubulization.  The  value  of  Biingner's  eft'orts  was  in  paving  the  way  for 
the  use  of  blood  vessels  in  tubulization.  His  experiments  were  followed  some 
years  later  by  those  of  Foramitti  (1904)  who  used  both  fresh  and  hardened 
arteries  with  success,  claiming  that  hardened  arteries  did  not  form  adhesions 
with  the  nerve  and  that  they  remained  longer  in  the  tissues  than  fresh  blood 
vessels.     Three    experiments    were    done    by    Foramitti.    the    longest    obser- 


TUBULIZATION  1 23 

\-ation  being  six  weeks,  and  the  largest  defect  bridged  I'^o  cm.  Both  Biingner 
and  Foramitti  found  that  the  elastic  tissue  in  the  artery  resists  absorption 
more  than  the  other  tissues  of  the  vessel  wall.  It  is  probable  that  the  value 
of  arterial  tubulization  depends  upon  llie  integrity  and  resistance  of  this 
elastic  tissue  layer.  Foramitti  prepared  the  arteries  by  stretching  them  over 
glass  tubes  and  hardening  them  in  5'  ,  formalin  solution  for  forty-eight  hours. 
They  were  then  washed  in  running  water  for  twenty-four  hours  and  boiled 
twenty  minutes,  after  which  they  may  be  kept  until  used  in  95%  alcohol. 
Such  tubes  were  employed  during  the  Russo-Japanese  War  by  Hashimoto 
and  Tokuoka  (1907),  and  also  in  the  Balkan  Wars,  however,  more  to  isolate 


Fig.  43. — Arterial  tubulization.  Two  epincural  mattress  sutures  of  fine  wa.xed  silk  are  passed 
at  opposite  points.  Both  ends  of  the  suture  are  threaded  and  passed  through  the  arterial  wall  from 
within  out.  Sutures  must  be  at  opposite  points  in  the  tube  to  prevent  the  nerve  being  turned  end  on 
against  the  arterial  wall. 


nerve  trunks  after  nerve  suture  than  to  bridge  nerve  defects.  Ruber's  (1919) 
more  recent  experiments  have  shown  that  such  hardened  arteries  remain 
in  the  tissues  more  than  six  months  without  being  absorbed  and  that  they  cause 
relatively  little  tissue  reaction. 

Tcchnic  of  Arterial  Tnhulizalion. — Prepared  arteries,  after  removal  from 
the  alcohol  and  immediately  before  using,  should  be  washed  in  salt  solution  and 
cut  to  approximately  the  size  required;  about  2  cm.  longer  than  the  distance 
to  be  bridged.  Two  mattress  sutures  of  tine  split  silk  are  passed  opposite  each 
other  on  the  nerve  trunk,  ajiiiroximately  5  mm.  from  the  nerve  end.  Each 
suture  is  first  passed  through  the  epineurium  and  both  ends  of  the  suture  are 
threaded  and  each  needle  is  carried  into  the  lumen  of  the  artery  and  passed 
through  the  arterial  wall  from  within  out.  The  threads  are  then  tied  on 
cither  side.  (See  Figs.  43  and  44.)  If  lK)lh  sutures  have  been  properly  placed 
the  nerve  will  be  held  within  the  lumen  of  the  arterial  tube  equidistantly  from 
either  side  of  the  arterial  wall. 


124         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Unless  the  two  sutures  are  cquidistanlly  placed  both  in  the  nerve  ami  the 
tube  the  nerve  ends  may  turn  end  on  against  the  wall  of  the  tube,  and,  by  adher- 
ing to  the  tube,  prevent  outgrowth  of  the  neuraxes;  or  if  the  peripheral  end 
becomes  adherent  neuraxes  will  be  unable  to  gain  entrance  and  though  down- 
growth  may  occur  from  the  central  stump,  penetration  into  the  distal  segment 
would  be  almost  impossible. 

Not  only  hardened  blood  vessels  but  fresh  veins  and  arteries  have  been 
used  to  bridge  nerve  defects.  Obtaining  fresh  veins  during  the  operation  is 
bothersome  and  time  consuming.  Furthermore,  in  fresh  veins  adhesions 
between  the  vein  and  the  nerve  are  more  apt  to  form,  as  also  between  the  vein 
and  the  surrounding  scar,  hence  not  only  do  they  otfer  little  or  no  protection 


Fig.  44. — Arterial  tubulization  completed.  The  dotted  lines  indicate  the  nerve  ends  within 
the  artery.  The  cross  section  shows  how  the  ner\'e  end  is  held  if  the  sutures  are  opposite  each  other 
in  both  the  nerve  and  artery. 

to  the  nerve  trunk  but  are  actually  harmful.  When  used  to  bridge  defects 
the  vein  walls  may  collapse  and  become  adherent  forming  connective  tissue 
within  the  lumen.  Nageotte  (1915)  found  as  an  additional  objection  that 
neuraxes  tended  to  grow  through  fresh  vessel  walls  into  the  surrounding  scar 
tissue. 

Eden  (191 7)  advocated  implantation  of  nerve  ends  into  the  normal  blood 
stream  in  intact  veins,  claiming  that  without  the  blood  stream  downgrowth 
does  not  take  place.  Experimentally  he  implanted  the  femoral  nerve  into  the 
femoral  artery  and  into  the  femoral  vein.  In  four  instances  he  tied  oft  the 
femoral  vein,  thus  preventing  a  flow  of  blood,  and  in  these  downgrowth  did  not 
occur,  while  in  the  remaining  six  not  tied  he  claims  the  distance  was  bridged. 
It  is  hardly  necessary  to  point  out  how  rarely  it  is  possible  to  avail  oneself 
of  a  neighboring  vein  in  this  manner  and  even  then  the  danger  of  throm- 
bosis contraindicates  such  a  fantastical  procedure,  though  it  may  be  possible 


TUBULIZATION  1 25 

for  iicuraxes  to  grow  first  into,  then  out  of  a  vein,  through  the  fibrin  which 
must  form. 

Since  Vanlair's  use  of  decalcified  bone  tubes  numerous  other  substances 
have  been  tried,  some  experimentally  and  others  only  clinically,  among  them : 
magnesium  tubes  (Payr,  1900);  gelatine  tubes  (Lotheisen,  1901);  galalith  tubes 
(casein  treated  by  formalin,  Auerbach,  1915);  agar  tubes  (Edinger,  1916);  agar 
tubes  filled  with  blood  serum,  rubber  tubes  filled  with  serum  (Steinthal,  191 7); 
(Heile  and  Hezel,  1915) ;  rubber  bandage  made  from  thin  rubber  (Meuriot  and 
Platon,  1918),  etc. 

Magnesium  tubes  are  readily  absorbed;  they  break  into  rather  sharp 
fragments  which  may  lacerate  the  tissues  hence,  if  for  no  other  reason,  are 
unsatisfactory.  Gelatine  tubes  are  somewhat  difficult  to  make  and  are  hard 
to  sterilize,  for  they  melt  unless  the  heat  is  carefully  controlled.  They  are 
also  too  rapidly  absorbed  for  use  in  nerve  bridging,  remaining  in  the  tissues 
only  about  three  months  according  to  Lotheisen.  Lotheisen  used  these  tubes 
only  four  times  in  the  human  and  no  experimental  work  in  their  application 
to  bridge  nerve  defects  was  done,  so  that  their  exact  fate  in  the  tissues  or 
the  tissue  reaction  which  they  may  cause  is  not  known. 

The  tubes  which  have  received  more  extensive  use  than  any  other  in  the 
bridging  of  nerve  defects  are  the  agar  tubes  of  Edinger.  In  Germany  these 
have  been  tried  both  clinically  and  experimentally  and  have  been  condemned 
thoroughly  not  only  as  of  no  value  but  actually  harmful.  EcUnger's  tubes 
were  used  by  Spitzy  (1917)  in  eleven  cases  without  regeneration.  In  addition 
he  tried  a  series  of  agar  tubes  filled  with  blood  scrum;  these  also  with  the  same 
result;  Blencke  (1917)  employed  agar  tubes  twenty-eight  times  without  any 
evidence  of  regeneration,  and  advised  that  "tubulization  with  Edinger's  tubes 
should  certainly  not  be  done;"  Miiller  and  Berblinger  (1917),  Hoftmann  and 
Spielmeyer  (r9i7),  Enderlen  and  Lobenhofter  (1917)  all  disapprove  of  the  use 
of  Edinger's  tubes  on  both  clinical  and  experimental  evidence.  They  concluded 
that  empty  agar  tubes  were  useless  in  bridging  nerve  defects  as  are  tubes  filled 
with  the  patient's  own  serum  which  were  claimed  to  be  preferable  to  empty 
agar  tubes.  Agar  does  not  offer  a  smooth  surface  for  the  downgrowth  of 
neuraxes  but  stimulates  outgrowth  of  scar,  and  rather  than  facilitating,  pre- 
vents regeneration.  After  extensive  histological  studies,  Spielmeyer  concluded 
that  Edinger's  tubes  were  not  only  useless  but  were  contraindicated  in  nerve 
surgery. 

Similar  objections  may  be  offered  in  the  case  of  rubber  tubing  as  used  by 


126         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Steinthal  (1917),  Heile  and  Hezel  (1915),  or  the  thin  rubber  tissue  advocated 
by  Meuriot  and  Platen  (1918) ,  since  rubber  remains  in  the  tissues  without  being 
absorbed  and  acts  constantly  as  a  foreign  body  stimulating  scar  tissue  forma- 
tion. Heile  and  Hezel  claim  that  rubber  is  slowly  absorbed  and  therefore 
found  no  contraindication  to  its  use.  This  is  of  course  contrary  to  the  obser- 
vations of  all  other  investigators. 

Fascial  Tubulization. — This  form  of  tubulization  was  used  by  Denk 
(1914)  in  the  wounded  of  the  Balkan  Wars,  as  a  means  of  isolation  of  nerves 
from  surrounding  scar.  Thirteen  cases  with  injuries  of  the  upper  extremity 
were  thus  treated  including  brachial  ple.xus  injuries.  In  the  latter  the  individ- 
ual nerve  trunks  were  not  enclosed  separately,  but  the  entire  plexus  en  masse. 
Necrosis  of  the  implanted  fascia  occurred  in  two  of  these  cases.  Just  what 
advantage  resulted  from  the  use  of  fascia  lata,  as  a  means  of  isolation  of  the 
nerve  trunk  or  in  conducting  nerve  fibers,  is  not  apparent  from  Denk's  report. 
Kredel  (191 5)  employed  fascia  lata  to  surround  a  sciatic  nerve,  using  suffi- 
cient fascia  to  have  encircled  the  nerve  twice,  and  yet  in  spite  of  this  the  fascial 
tube  contracted  about  the  nerve  constricting  it  and  causing  severe  pain, 
necessitating  a  second  operation  for  removal  of  the  fascia  and  nerve  section. 
Histological  examination  of  the  tissues  removed  at  operation  showed  that  the 
fascia  was  adherent  to  the  nerve,  excessive  scar  tissue  had  fonned  and  that  no 
free  space  could  be  made  out  between  the  nerve  and  the  tube.  Kredel  suggested 
that,  on  account  of  contraction  of  the  fascia,  it  should  never  be  used  to  surround 
the  nerve  but  should  be  employed  rather  as  a  sheet  to  be  passed  beneath  the 
nerve  to  form  a  smooth  nerve  bed. 

Kirk  and  Lewis  (1915)  recommended  fascia  lata  tubulization  to  bridge 
nerve  defects,  as  Vanlair  had  used  decalcifted  bone  tubes,  and  Foramitti  hardened 
arteries.  Kirk  and  Lewis  found  that  downgrowth  of  neuraxes  will  occur  when 
hemorrhage  within  the  fascial  tube  is  prevented  and  that  contraction  of  the 
fascia  about  the  nerve  may  be  minimized  by  making  the  lumen  of  the  fascial 
tube  twice  as  large  as  the  circumference  of  the  nerve  to  be  bridged.  They 
believe  that  secondary  contraction  of  the  fascia  may  be  avoided  "if  the  fascia  is 
sutured  into  place,  and  is  subjected  to  the  same  conditions  as  regard  stress  and 
strain  as  in  the  part  from  which  it  was  removed."  This  of  course  would  seem 
difficult  of  attainment.  They  also  believe  that  fascial  tubes  should  not  be 
placed  in  a  wound  in  the  presence  of  fresh  scar,  since  it  tends  to  undergo 
cicatricial  contraction.  The  very  precautions,  which  apparently  it  is  essen- 
tial  to   observe  in  order  to  use  fascia  lata   tubulization  successfullv,   make 


TLTBULIZATION  1 27 

its  usefulness  extremely  limited,  since  the  indication  for  tubulization  in  nerve 
injures  is  either  to  avoid  scar  contraction  about  a  sutured  nerve,  or  as  a  chan- 
nel down  which  neuraxes  may  grow.  While  it  is  possible  by  accurate  suturing 
to  prevent  blood  from  the  wound  running  into  the  fascial  tube,  by  making 
the  fascia  fit  snugly  about  the  nerve  the  danger  of  constriction  by  contraction 
of  the  fascia  is  increased.  It  is  very  difficult  to  obtain  complete  hemostasis 
from  the  severed  nerve  ends  when  these  are  not  brought  together  either 
directly  or  by  multiple  grafts,  since  the  ends  dangle  free  within  the  lumen 
of  the  tube  and  some  hemorrhage  is  nearly  certain  to  occur.  Hemorrhage 
within  the  lumen  causes  scar  tissue  formation,  and  according  to  Kirk  and 
Lewis  this  may  prevent  downgrowth  of  the  neuraxes;  while,  on  the  other 
hand,  a  fascial  tube  in  the  presence  of  fresh  scar  tissue  within  the  wound 
stimulates  scar  formation  and,  therefore,  is  also  contraindicated.  Consequently 
fascial  tubulization  must  of  necessity  have,  if  any,  a  very  limited  field  of  useful- 
ness. While  in  a  measure  successful  experimentally,  though  less  than  other 
methods,  its  application  to  human  nerve  surgery  cannot  be  commended. 

Cargile  membrane  has  been  used  in  various  fields  of  surgery  to  prevent 
adhesions.  The  application  of  this  membrane  to  nerve  surgery  as  a  means  of 
isolation  of  nerve  trunks  was  suggested  by  Sherren  (igo6).  Unfortunately 
cargile  membrane  is  more  or  less  useless  for  this  purpose,  since  it  is  rapidly 
absorbed,  remaining  in  the  tissues  no  longer  than  catgut  sutures  even  when  used 
in  double  or  triple  layers.  Obviously  this  is  too  short  a  time  to  be  of  much 
value  in  nerve  surgery.  Huber  (1919)  found  that  cargile  membrane  fixed  in 
alcohol  remained  in  the  tissues  from  five  to  six  m.onths  without  absorption,  and 
without  causing  any  particular  tissue  reaction.  Ordinary  cargile  is  placed  in 
95%  alcohol  and  allowed  to  remain  at  Icasi  a  week  or  ten  days  before  using. 
Immediately  before  using  it  is  dipped  in  absolute  alcohol,  and  the  alcohol 
allowed  to  evaporate  before  placing  the  membrane  in  the  wound.  It  is  of 
greater  value  in  preventing  adhesions  following  suture  or  nerve  grafting  and 
after  nerve  liberation  than  as  a  means  of  tubulization  to  bridge  nerve  defects- 
Ruber's  cargile  membrane  is  particularly  useful  for  it  is  readily  obtained  and 
easily  applied,  in  that  it  is  merely  wrapped  about  the  nerve  trunk  or  graft. 

REFERENCES 

.\uERBACH,  S.:  Galalith  fiir  Tubulization  der  Nerven  nach  Neurolysen  und  Nervenniihten 

Miinchen.  med.  Wchnschr.,  v.  62:  1915,  p.  1457. 
Blencke,  a.:  Ein  weiterer  Beitrag  zu  den  Ueberbruckungsversuchen  von  Nervendefekten 

mit  Edinger-RiJhrchcn,  Zcnlralbl.  f.  Chir.,  v.  44:   1917,  p.  236. 


1 28         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

BuNGNER,    O.   VON.:  Uebcr   die   Degenerations-  und    Regenerations- Vorgange  an  Nerven 

nach  Verletzungen,  Beitr.  z.  path.  .\nat.  u.  z.  allg.  Path.,  v.  lo:   iSgi,  p.  321. 
Denk,  W.:  Uber  Schussverletzung  der  Nerven,  Beitr.  z.  klin.  Chir.,  v.  91:  1914,  p.  217. 
Eden,  R.:  Sind  zur  Ueberbriickung  von  Nervendefekten  die  Verfahren   der  Tubulisation 

und  der  Nerventransplantation  zu  empfehlen,  Zentralbl.  f.  Chir.,  v.  44:   1917,  p.  138. 
Spontane  Nervenregeneration  ini  stromenden  Blut.  (Naturwissenschaftl.  med.  Gesellsch. 

zu  Jena,  23,  Nov.,  1916),  Munchen.  med.  Wchnschr.,  1917,  6. 
Edinger,   L.:  Uber   die  Vereinigung  getrennter  Nerven.     Grundsatzliches  und  Mitteilung 

eines  neuen  Verfahrens,  Munchen.  med.  Wchnschr.,  v.  63:   1916,  pp.  225-228. 
Enderlin  and  Lobenhoffer:  Zur  Ueberbriickung  von   Nervendefekten,   Munchen.   med. 

Wchnschr.  (Feldarztl.  Beil.,  Nr.  7),  v.  64:   1917,  p.  1013. 
DOPFNER,  K.:  Zur  Methodik  der  Naht  peripheren  Nerven,  Munchen.  med.  Wchnschr.,  v. 

62:   1915,  p.  526. 
FoRAMiTTi,  C:  Zur  Technik  der  Nervennaht,  .\rch.  f.  klin.  Chir.,  v.  73:  1904,  p.  643. 
Gluck:  Ueber  Transplantation,   Regeneration   und  entziindliche  Neubildung,   Berl.   klin. 

Wchnschr.,  v.  18:   1881,  pp.  529-554. 
Hashimoto,  T.  and  Tokuoka,  H.:  Ueber  die  Schussverletzungen  peripherer  Nerven  und 

ihre  Behandlung  (Tubulization),  Arch.  f.  klin.  Chir.,  v.  84:  1907,  p.  354. 
Heile  and  Hezel:  Unsere  bisherigen  Erfahrungen  bei  der  Behandlung  im  Kriege    ver- 

letzter  peripheren  Nerven,  Beitr.  z.  klin.  Chir.,  v.  96:   1915,  P- 299. 
Hoffmann,  G.  and  Spielmeyer,  W.:  Zur  Kritik  des  Edingerschen  und  des  Betheschen 

Verfahrens  der  Ueberbriickung  griisserer  Nervenliicken,   Miinchen.   med.  Wchnschr., 

v.  64:   1917,  p.  97  (Feldarztl.  Teil.,  Nr.  3). 
Ruber,  G.  C:     Operative  treatment  of  peripheral  nerves  after  severance,  more  particularly 

after  loss  of  substance — a  critical  review,  J.  Lab.  &  Clin.  M.,  v.  2:  Sept.,  191 7,  p.  837. 

A  study  of  operative  treatment  for  loss  of  nerve  substance  in  peripheral  nerves,  J.  Mor- 

phol.,  V.  11:   1895,  p.  629. 
Transplantation  of  peripheral  nerves,  .\rch..  Neurol.  &  Psychiat.,  v.  3:  no.  4,  April,  1920, 

P-  437- 
Kirk.  C.  and  Lewis,  D.:  Fascial  tubulization  in  the  repair  of  nerve  defects,  J.  A.  ]\L  A.i 

V.  65:  Aug.,  1915,  p.  486. 
Kredel,  L.:  Ueber  das  Verhalten  der  auf  operierte  schussverletzter  Nerven  iiberptlanzten 

Fascienlappen,  Zentralbl.  f.  Chir.,  v.  42:   1915,  p.  201. 
Kruger:  Beobachtungen    und    Erfahrungen    bei    Untersuchungen   und   Operationen   von 

Schussverletzungen  der  peripheren  Nerven  mit  besonderer  Beriicksichtigung  der  veral- 

teten  Falle  (Gesellsch.  f.  Natur-u.  Heilkunde  ze  Dresden,  12,  Jan.,  1917),  Miinchen.  med. 

Wchnschr.,  v.  64:  1917,  p.  913. 
Lotheisen,  G.:  Zur  Technik  der  Nerven  und  Sehnennaht,  Arch.  f.  klin.  Chir.,  v.    64:    1901 

p.  310. 
Maxjclaire:  Suture  nerveuse  tubulaire  avec  des  trachees  despetits  animaux,  Paris  med. 

V.  6:   1916,  p.  39. 
Meuriot,  H.  et  Platon:  100  observations  d'isolement   des  nerfs  par  manchonnage  au 

caoutchouc,  Bull,  et  mem.  Soc.  de  Chir.  de  Par.,  v.  44:  14  Mai,  1918,  p.  850. 


TUBULIZATION  1 29 

MuLLER,  O.  and  Berblinger,  W.:  Das  Endergebnis  einer  nach  der  Edingerschen  Methode 

(Agarrohrchen)  vorgenommenen  Ueberbriickung  des  nervus  ulnaris  mit  anatomischer 

Untersuchung,  Berl.  klin.  Wchnschr.,  v.  54:   igiy,  p.  nog. 
Nageotte,   J.:  Le  proces  de  la  cicatrisation  des  nerfs,  Rev.  neurol.,  v.   22:  1914-15,  p. 

505- 
Payr,   E.:  Beitrage   zur  Technik   der   Blutgefass-  und  Nervennaht   nebst    Miltheilungen 

uber  Vervvendung  eines  resorbirbaren  Metalles  in  der  Chirurgie,  Arch.  f.  klin.  Chir., 

V.  62:  1900,  p.  67. 
Platt,  H.:  Results  of  bridging  aps  in  injured  nerve  trunks  by  autogenous  fascial  tubuliza- 

lion  and  autogenous  nerve  grafts,  Brit.  J.  Surg.,  v.  7:  Jan.  1920,  p.  384. 
Sherre.x,  J.:  Some  points  in  the  surgery  of  the  peripheral  nerves,  Edinburgh  M.  J.,  v.  20: 

1906,  p.  297. 
Spitzv,  H.:  Bemerkung  zur  Ueberbriickung  von  Nervendefekten,  Munchen.  med.  Wchnschr. 

v.  64:  1917,  p.  372  (Feldarztl.  Bail.,  Nr.  11). 
Steixthal:  Die  Ueberdeckung  von  Grosseren  Nervendefekten  mittels  Tubularnaht,  Zen- 

tralbl.  f.  Chir.,  v.  44:   1917,  no.  29,  p.  646. 
Stracker,  O.  :  Zur  Prognostik  der  Operationen  an  peripheren  Nerven,  Wien.  klin.  Wchnschr. 

v.  29:  1916,  p.  225. 
Zu  den  Ueberbriickungsversuchen  von  Nervendefekten,  Zentralbl.  f.  Chir.,  v.  43:   1916, 

p.  985. 
Vanlair,  C:  Nouvelles  recherches  e.xperimentales,  sur  la  regeneration  des  nerfs  peripheri- 

ques,  Arch,  de  Biologic,  v.  100:   1SS5,  p.  1605. 


CHAPTER  VI 
NERVE  LIBERATION 

Nerve  conductivity  may  be  interrupted  by  pressure  upon  the  nerve  trunk 
without  any  loss  of  anatomical  continuity  and  probably  without  severe  his 
tological  changes  in  the  nerve  fiber.  Concerning  this  point  there  is  relatively 
little  experimental  evidence,  yet  the  anatomical  integrity  of  the  nerve  fiber  is 
indicated  clinically.  In  certain  cases  with  signs  of  complete  interruption  of 
conductivity,  almost  immediate  return  of  function  has  followed  liberation  of 
the  nerve  trunk — in  some  instances  within  twenty-four  hours.  In  these  cases 
the  return  has  been  too  rapid  to  admit  of  re-estabhshment  of  function  on 
the  basis  of  regeneration  of  the  nerve  fiber.  When  such  rapid  return  of  function 
occurs  it  is  probable  that  the  nerve  fiber  is  intact  anatomically,  and  that  only 
its  power  of  conductivity  has  been  inhibited  by  pressure  exerted  upon  the  nerve 
fibers.  It  is  well  known  that  by  physical  means  alone,  such  as  cold,  nerve 
conductivity  may  be  interrupted  without  any  demonstrable  anatomica- 
changes  and  that  conductivity  may  be  re-established  when  the  nerve  is  warmeds 
thus  showing  that  propagation  of  stimuli  along  the  nerve  trunk  may  be  abolished 
without  anatomical  interruption. 

Pressure  on  a  nerve  may  be  due  to  scar  or  callus  about  the  nerve  trunk- 
or  to  the  formation  of  scar  within  the  nerve  trunk;  more  often  both.  Intra 
neural  scar  alone  may  be  due  to  direct  trauma,  producing  minute  hemorrhages 
within  the  nerve,  or  indirect  from  the  passage  of  a  bullet  of  high  velocity  through 
the  tissues  near  a  nerve,  probably  setting  up  in  the  nerve  trunk  sufficient  vibrar 
tion  to  produce  hemorrhage,  though  the  exact  mechanism  of  such  injuries  if 
not  proven. 

An  electrical  examination  of  the  nerve  should  invariably  be  made  during 
the  operation.  For  this  purpose  only  an  induction  coil  current  should  be  used 
since  the  direct  current  may  burn.  A  Porter  induction  coil  or  a  Lewis  Jones 
sledge  coil  will  be  found  convenient  and  satisfactory.  Complicated  electrodes 
are  less  useful  than  plain  copper  wires  of  fine  caliber.  These  may  be  insulated 
by  glass  beads,  varnish  or  sterile  rubber  tubing.  The  writer  prefers  to  use  plain 
naked  copper  wire  which  is  readily  sterilized  by  boiling  and  does  not  get  out  of 
order  as  do  the  more  complicated  electrodes.     One  wire  is  controlled  by  the 

130 


NERVE    LIBERATION  I3I 

surgeon,  the  other  by  the  assistant,  and  with  a  httle  attention  the  wires  may 
be  kept  apart. 

The  minimal  threshold  to  obtain  contraction  in  normal  nerves  for  the  indi- 
vidual is  obtained  in  nerves  exposed  in  the  wound,  and  the  electrodes  are  then 
applied  to  the  injured  nerve  and  the  current  gradually  increased.  Strong 
currents  spread  in  the  tissues,  mask  the  response  and  should,  therefore,  be 
avoided.  The  nerve  is  usually  isolated  on  glass  rods  or  glass  hooks  and  tested 
not  only  above  but  below  and  in  the  scar.  If  a  response  is  obtained  in  the 
distal  distribution  complete  nerve  section  should  not  be  done,  though  partial 
suture  of  the  more  damaged  portions  of  the  nerve  trunk  may  be  indicated  if 
these  do  not  conduct.  Rarely  may  a  response  be  obtained  in  the  injured  nerve 
by  stimulation  below  the  level  of  the  injury  while  no  response  may  be  elicited 
by  stimulation  above  or  at  the  point  of  the  injury.  Such  is  Erb's  paradoxical 
response  which  is  found  in  cases  with  only  slight  compression.  Slight  physical 
changes,  may  interrupt  nerve  conductivity,  apparently  without  structural 
changes  in  the  nerve  liber.  In  Erb's  paradoxical  response  interruption  of  con- 
ductivity is  confined  to  the  point  of  injury  and  is  entirely  comparable  to  condi- 
tions in  experimental  interposition  on  a  muscle-nerve  preparation  of  a  nar- 
cotizing chamber,  or  any  other  set  of  physical  changes  which  lead  to  local 
functional  depression  without  destruction  of  the  neuraxes.  In  such  experi- 
ments the  passage  of  an  impulse  through  the  narcotized  area  is  prevented, 
while  below  it  conductivity  is  normal.  In  one  case  in  which  Erb's  paradoxical 
response  was  found,  stimulation  of  the  nerve  immediately  after  liberation  and 
above  the  level  of  the  injury  was  followed  by  contraction  in  the  peripheral  dis- 
tribution, thus  indicating  how  relatively  slight  and  transitory  may  be  the 
interference  in  nerve  conductivity. 

In  nerves  completely  severed  no  response  will  be  obtained,  though  in  rare 
instances  enough  stray  fibers  may  have  penetrated  the  scar  to  give  some  slight 
response.  The  amount  of  the  response  and  the  location  of  the  response  as 
well  as  the  point  at  which  the  nerve  is  stimulated  are  important  factors.  A 
definite  positive  response  in  whole  muscles  is  of  great  value  and  indicates 
that  there  is  some  physiological  conductivity  in  the  nerve  fibers.  A  nega- 
tive response,  it  must  be  recalled,  is  of  little  value,  since  though  the  neuraxes 
may  have  penetrated  the  scar  they  may  not  yet  have  formed  their  peripheral 
connections.  (See  Figs.  45,  46,  47,  48.)  Great  care  must  be  taken  to  observe 
accurately  the  motor  contractions  on  stimulation  of  the  nerve.  For  this 
purpose  the  extremity  must  be  well  exposed  and  considerable   judgment  is 


1.^2 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


needed  to  determine  whether  the  response  is  the  result  of  stimulation  of  the 
injured  nerve  or  another  nerve  whose  muscles  may  stimulate  the  action  of  the 
nerve  in  question. 


Level     o, 


Fig.  45. 


Fig.  46. 


Lev. I 


Le..L   .( 


Fig.  47. 


Fig.  48. 


Figs.  45,  46,  47,  48. — Schematic  drawing  to  show  why  a  negative  electrical  response  may  be 
obtained  from  stimulation  of  the  nerve  trunk  at  the  level  of  the  injury  even  though  downgrowth  of 
neura.xes  is  taking  place.  A  positive  response  is  not  to  be  e.xpected  until  the  neuraxes  have  reached 
the  muscle  and  have  formed  motor  end  plates.  Fig.  45,  no  response;  Fig.  46,  no  response;  Fig.  47, 
no  response;  Fig.  48,  response. 

The  density  of  intraneural  scar  may  be  estimated  by  injecting  salt  solution 
into  the  nerve  at  the  point  of  injury.     Normally  a  solution  will   penetrate 


NERVE    LIBERATION  I33 

between  the  funiculi  and  cause  a  fusiform  swelling  over  a  considerable  distance 
depending  on  the  amount  of  fluid  injected  and  the  pressure.  When  the  scar  is 
dense,  fluid  will  not  enter,  and  the  nerve  trunk  remains  unaltered  in  size.  If, 
on  the  other  hand,  fluid  injected  under  pressure  does  penetrate,  the  intraneural 
scar  is  neither  extensive  nor  dense.  Injection  of  fluid  under  pressure  serves  not 
only  to  determine  the  density  of  the  scar,  but  may  also  be  used  as. a  means  of 
breaking  up  adhesions  between  the  funiculi  and  thus  perform  as  it  were  an 
internal  liberation.  In  rare  instances  a  longitudinal  incision  in  the  sheath  of  the 
nerve  may  be  made  and  the  interior  of  the  nerve  investigated.  Some  surgeons 
attempt  to  separate  the  funiculi  when  they  are  adherent  to  each  other  by  insert- 
ing between  the  funcili  fine  sharp-pointed  scissors  which  are  then  carefully 
opened.  If  the  incision  in  the  sheath  is  made  at  the  level  of  an  internal 
nerve  plexus  with  numerous  intercommunications,  these  may  be  mistaken  for 
adhesions  and  destroyed  or  broken  together  with  existing  adhesions.  In  the 
author's  experience  such  intraneural  dissection  is  rarely  justified  except  perhaps 
at  a  level  where  funicular  separation  is  known  to  exist  normally.  If  intraneural 
injection  of  salt  solution  does  not  suflice  as  an  internal  liberation  sharp  dissection 
will  not,  since  without  means  to  prevent  adhesions  reforming  in  the  nerve  trunk, 
old  and  new  adhesions  occur.  When  intraneural  injection  of  salt  solution  does 
not  liberate  and  definite  scar  contraction  remains,  excision  had  better  be  done 
than  sharp  intraneural  dissection  of  scar.  However,  if  the  nerve  bulb  is  fusi- 
form and  relatively  soft  it  can  be  taken  that  marked  infiltration  of  scar  tissue 
is  not  present  and  excision  should  not  be  done. 

In  order  to  determine  whether  nerve  section  should  be  done  or  not,  the 
surgeon  must  be  familiar  witii  the  complete  neurological  findings  and  the  prog- 
ress of  the  case  as  noted  at  each  examination,  and  this  information  must  be 
fitted  in  with  the  anatomical  findings  at  operation — the  results  of  direct  electrical 
stimulation,  palpation  of  the  nerve  trunk  and  injection  of  salt  solution.  Price, 
Feiss  and  Terhune  (1919)  are  of  the  opinion  that  after  considering  all  of  the 
evidence  if  doubt  exists  as  to  whether  nerve  liberation  or  nerve  suture  is  indicated, 
excision  and  nerve  suture  should  be  done.  The  interval  between  the  date  of 
injury  and  operation  is  an  important  factor  to  consider.  When  earh'  nerve 
exploration  is  performed  a  conservative  course  may  be  pursued,  which  in  late 
cases  might  not  be  justified.  Within  six  to  eight  weeks  following  nerve  libera- 
tion some  signs  of  returning  function  should  be  evident.  If  these  are  not  found 
within  this  period  the  conclusion  is  warranted  that  in  place  ol  nerve  lil)eration 
nerve  suture  should  have  been  done,  and  it  should  then  be  undertaken. 


134         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

In  performing  nerve  liberation  the  surrounding  scar  should  be  excised  or 
infolded  on  itself,  callus  chiselled  away  and  the  bone  hammered  so  as  to  prevent 
reformation  of  exostoses.  Whenever  possible  the  nerve  should  be  trans- 
posed to  a  new  bed,  preferably  into  the  fascial  planes  between  muscles  or  a 
new  bed  made  for  the  nerve.  The  nerve  should  not  be  imbedded  in  torn  or  cut 
muscles,  for  the  hemorrhage  from  the  muscle  fibers  increases  scar  tissue  formation 
and  may  cause  strangulation  of  the  nerve.  When  a  new  bed  cannot  be  made  and 
the  surrounding  scar  is  extensive  or  can  be  only  partially  removed  the  nerve 
may  be  surrounded  with  Huber's  cargile  membrane.     (See  page   127.)     In 

.„'^''c  '^^f!    ~      a„  .„  ,o„  certain  instances  when  the  nerve  is  constric- 

10     20   30   40     50  60   70     80  90  100 

ted  by  small   circumscribed   bands,  minute 
longitudinal  incisions  into   the  nerve  trunk 
called   "hersage"   may  be  done.     The  inci- 
sions are  made  through  the  epineurium  and 
Chart    II. — Table    to   show  the  rela-  ■  1      ,        ......  ...  -,      . 

tive  frequency   of    nerve    liberation    and    SO   to   avoid   the   tumcull  it  possible.       In  ISO- 

nerve  suture  in  1200  nerve  operations,     lated  cases  this  is  an  important  adjunct  to 
liberation  of  the  nerve  trunk. 

The  results  of  nerve  liberation  done  in  properly  selected  cases  have  been 
most  gratifying.  Price,  Feiss  and  Terhune  found  that  65%  showed  improve- 
ment following  nerve  liberation;  of  these  complete  return  of  voluntary  movement 
was  found  in  20%,  almost  complete  return  in  22,'^Q  and  return  of  sensation  and 
definite  evidence  of  some  nerve  regeneration  in  22%.  These  statistics  were 
made  after  extensive  experience  and  are  the  result  of  very  careful  observation, 
and  agree  approximately,  with  the  result  of  other  workers;  however,  some 
claim  as  high  as  80%  of  improvements.  Nerve  liberation  has  given  the  most 
satisfactory  results  of  any  form  of  operative  treatment,  but  it  should  be  borne 
in  mind  that  it  is  only  in  cases  with  relatively  little  anatomical  injury  that  nerve 
liberation  is  advised. 

REFERENCES 

Burrows,  J.  Le  F.  and  Carter,  H.  S.:  Preliminary  note  on  investigation  upon  1000  con- 
secutive cases  of  peripheral  nerve  injury,  Brit.  M.  J.,  v.  2:  1918,  p.  535. 

Delageniere,  H.:  Traitement  chirurgical  des  blessures  des  nerfs;  .  .  .  245  cas  de  sutures 
et  118  liberations  suivies  par  le  Dr.  Tinel,  Bull,  et  mem.  Soc.  de  Chir.  de  Par.,  v.  44: 

1918,  p.  524. 

Elsberg,  C.  a.:  Technic  of  nerve  suture  and  nerve  grafting,  J.  A.  ]M.  A.,  v.  73:  Nov.  8, 

1919,  pp.  1422-1427. 

Frazier,  C.  H.:  Surgical  problems  in  the  reconstruction  of  peripheral  nerves,  Ann.  Surg., 
V.  71:  January,  1920,  p.  i. 


NERVE    LIBERATION  I35 

Lewis,  Deax:  Principles  of  peripheral  nerve  surgery,  J.  A  M.  A.,  v.  75:  July  10,  lO-o,  no. 

-'.  P-  73- 
Morton',    C.    A.:  Operative  findings  in  thirty  cases  of  gunshot  injury  of  nerves,  Bristol 

M.-Chir.  J.,  V.  36:   iQiS-igiQ,  p.  55. 
Noo.v,  A.:  Observations  on  250  cases  of  gunshot  wounds  of  the  peripheral  nerves,  J.  Roy. 

.\rmy  Med.  Corps,  London,  v.  31:   1918,  p.  39. 
Price,  G.  E.,  Feiss  and  Terhune:  Nerve  injuries,  .\rch.,   Neurol.  &  Psychiat.,  v.   i:   1919 

P-  547- 
Peripheral  nerve  injuries,  J.  Nerv.  &  Ment.  Dis.,  v.  50:   1919,  p.  551. 
Spear,  I.  J.  and  Babcock,  W.  W.  :  Peripheral  nerve  injuries  concomitant  to  gunshot  wounds, 
Arch.,  Neurol.  &  Psychiat.,  v.  2:   1919,  p.  253. 


CHAPTER  VII 
TECHNIC  OF  NERVE  SUTURE 

Arrangement  of  the  Operative  Field. — The  Umb  must  be  placed  so  as  to 
give  the  easiest  access  to  the  operative  field.  Each  position  will  be  described 
in  connection  with  each  nerve.  Most  nerve  operations  are  long  and  tedious 
so  that  better  work  will  be  done  if  all  are  made  somewhat  comfortable,  in 
most  instances  those  operating  being  seated.  When  it  is  necessary  to  hold 
the  extremity  in  some  special  position  it  should  be  held  by  apparatus  rather 
than  by  an  assistant.  By  mechanical  means  the  limb  is  held  steady  and 
slight  movements  avoided  which  might  cause  considerable  inconvenience 
by  pulling  out  or  deranging  a  graft  as  it  is  being  placed.  Sheets  should  be 
placed  so  as  to  allow  movement  of  the  extremity  without  disturbing  the  opera- 
tive field.  This  is  necessary  when  the  position  of  the  limb  must  be  changed  in 
order  to  bring  the  nerve  ends  in  approximation,  or  if  another  incision  or  exposure 
must  be  made.  As  a  practical  point  it  will  be  found  helpful  in  operations  on  the 
lower  extremity  to  cover  that  part  of  the  leg  and  foot  not  involved  in  the  opera- 
tive field  with  sterile  stockinette,  and  in  operations  on  the  upper  extremity,  the 
forearm  and  hand.  When  the  hand  is  not  to  be  included  in  the  operation  it 
should  be  covered  with  a  tight-fitting  rubber  or  cotton  glove  covering  each 
finger  separately.  These  coverings  should  fit  snugly  and  thus  permit  more 
accurate  observation  of  individual  muscular  movements  and  palpation  of  the 
individual  tendons  during  direct  electrical  examination  of  the  nerve  trunk. 

Suture  Materials. — Plain  ooo  catgut  and  the  finest  possible  waxed  silk 
are  used.  Slight  tissue  reaction  on  the  part  of  the  mesoblastic  tissues  only 
was  found  in  experimental  work  in  nerve  suture  with  waxed  silk  sutures.  A  few 
cells  surrounded  the  sutures  but  never  suflicient  to  form  any  block  to  the  down- 
growth  of  the  neuraxes  even  in  such  small  nerves  as  the  peroneal  of  the  rabbit  or 
the  sciatic  of  the  guinea  pig.  The  neuraxes  simply  glide  in  a  gentle  curve 
around  the  suture  points  without  showing  tortuosity,  Perroncito  spirals  or  any 
other  evidences  of  resistance  to  their  passage.  (See  Fig.  49.)  In  experimental 
studies  of  various  suture  materials  Sargent  and  Grenfield  (1919)  found  that 
while  silk  gave  rise  to  but  little  tissue  reaction,  sutures  treated  chemically, 
as    chromic    catgut    and    iodized  catgut,   caused   a  more  pronounced  tissue 

136 


TECHNIC    OF    NERVE    SUTURE 


137 


reaction.  In  ner\-e  suture,  especially  in  nerve  transplantation,  where  a  mini- 
mum of  tissue  reaction  is  desired,  these  suture  materials  should  not  be  used. 
Ordinary  Corticelli  AAA  black  silk  is  untwisted  and  separated  into  three 
strands.  Each  of  these  is  then  thoroughly  waxed  with  bee's  wax  and  threaded 
on  line  curved  needles.  By  passing  the  point  of  the  needle  through  the  suture 
two  or  three  times  and  then  threading  one  end  of  the  suture  through  the  eye 


P'lG.  49. — Longitudinal  section  through  a  sutured  nerve  at  the  point  of  suture.  Wa.'ied  silk 
was  used.  Note  the  comparatively  slight  tissue  reaction  around  the  sutures  5.5.  (Ranson  pyridine 
silver  stain.) 


the  thread  may  be  fastened  without  tying.  In  this  manner  the  suture  is 
held  as  if  tied  but  without  a  knot  being  formed,  and  follows  through  the  tissues 
without  offering  any  resistance  as  may  occur  when  a  knot  is  present.  The 
threaded  needles  are  then  passed  through  a  cloth,  sterilized  and  rewaxed  with 
sterile  wax  just  before  using.  Silk  sutures  threaded  in  this  manner  are  easy 
to  handle  and  tie,  and  slip  readily  through  the  nerve  without  drawing  in  the 
epineurium.  These  points  are  of  importance  in  the  fine  work  necessary  for 
nerve  grafts. 


138         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Instruments. — Sharp  knives  having  small  thin  blades  should  be  used  to 
cut  through  the  nerve,  especially  if  serial  sections  are  done,  to  determine  the 
level  at  which  suture  is  to  be  made.  Neither  the  nerve  trunk  nor  a  nerve  graft 
should  be  cut  with  scissors,  since  scissors  tend  to  crush  the  nerve  ends.  A  very 
satisfactory  knife  is  one  with  changeable  blades  which  usually  are  thinner  than 
the  blades  of  an  ordinary  knife  or  even  than  the  blade  of  a  safety  razor.  The 
latter  is  used  by  some  as  a  scapal,  the  blade  being  held  with  artery  forceps. 
Fine  mosquito  forceps  should  be  kept  for  grasping  the  epineurium  or  the  fine  silk 
sutures.  If  mosquito  forceps  are  used  for  other  purposes  they  soon  lose  their 
precision  and  are  then  of  little  value  for  delicate  work.  Fine  mouse-tooth  forceps 
are  used  to  grasp  the  epineurium  in  manipulating  and  dissecting  the  nerve,  and 
anatomical  forceps  to  tie  the  nerve  sutures,  the  latter  may  also  be  employed 
satisfactorily  as  a  needle  holder  and  are  better  than  a  clasp  holder  since  the 
epineural  suture  may  be  disturbed  in  efforts  to  release  the  clasp.  A  sterilizable 
electrode  is  an  essential  in  any  nerve  operation.  A  specially  made  electrode 
may  be  procured  or  naked  copper  wire  used.  (See  page  130.)  Thus  few  special 
instruments  are  needed. 

Anesthetic. — The  long  duration  of  many  nerve  operations  requires  that 
extreme  care  be  taken  with  the  anesthetic.  If  a  general  anesthetic  is  used  it 
should  be  administered  so  that  a  minimum  of  ether  is  given.  Perhaps  the 
most  satisfactory  general  anesthesia  in  the  author's  cases  have  been  those  in 
which  warmed  vapor  has  been  given  and  one  of  the  special  ether  apparatuses 
used.  With  this  method,  even  alter  three  or  four  hours  of  anesthesia,  no  unto- 
ward effects  have  been  noted.  In  place  of  ether,  gas  and  oxygen  may  be  used 
and  good  anesthesia  obtained,  even  for  prolonged  operations.  Local  anesthesia 
is  of  particular  value  in  many  nerve  operations.  Not  only  is  a  satisfactory 
anesthesia  obtained,  but  the  hemorrhage  and  oozing  from  scar  tissue  is  dimin- 
ished by  the  adrenalin  and  the  pressure  of  the  solution.  One-half  of  1% 
novocain  solution  is  used  containing  icc.  of  adrenalin  chlorid  (i-iooo)  to  each 
50  cc.  of  solution  used.  In  place  of  injecting  the  solution  with  the  usual  hypo- 
dermic syringe,  either  gravity,  or  pressure  may  be  used.  Farr  has  designed  a 
very  efficient  pressure  method,  having  the  solution  in  a  tank  under  pressure 
and  then  injecting  into  the  tissues  with  a  special  nozzle  syringe.  The  pressure 
permits  very  easy  and  rapid  infiltration  with  a  minimum  of  pain  and  discomfort 
to  the  patient. 

General  Operative  Technic. — If  the  skin  incision  is  begun  below  and 
extended  upward,  much  of  the  troublesome  venous  bleeding  may  be  avoided. 


TECHNIC  OF  NERVE  SUTURE  a3Q 

By  this  procedure  all  veins  are  cut  and  tied  first  at  the  lowest  point  and  further 
bleeding  from  the  same  vein  is  obviated  as  the  incision  is  lengthened.  Super- 
ficial scar  when  present  should  be  excised  as  completely  as  possible.  The  skin 
edges  should  be  well  undermined  so  as  to  include  the  fatty  fascial  layer  bringing 
the  fat  with  the  skin  edges  into  the  new  line  of  closure.  Unless  this  is  done, 
the  line  of  union  is  certain  to  stretch  and  a  broad  scar  result.  The  Haps  should 
be  prepared  for  closure  before  searching  for  the  nerve,  all  bleeding  points  tied, 
and  the  undermined  edges  packed  with  gauze  after  making  certain  that  a  proper 
line  of  closure  has  been  insured.  Unless  this  is  done  before  nerve  suture  is 
accomplished,  the  extra  maneuvering,  coincident  with  preparation  of  the  flaps, 
may  derange  the  delicate  line  of  nerve  sutures. 

When  the  deep  scar  is  extensive,  it  is  best  to  identify  the  nerve  in  normal 
areas  both  above  and  below  the  injury,  selecting,  if  possible,  such  points 
within  the  field  as  offer  anatomical  guides  to  the  nerve  in  question.  Thus, 
for  example,  the  ulnar  nerve  is  recognized  in  the  ulnar  groove  behind  the 
elbow,  or  by  its  relation  to  the  flexor  carpi  ulnaris  tendon  in  the  forearm;  the 
median  nerve  just  under  the  mesial  border  of  the  biceps  muscle,  etc. 

Before  freeing  the  nerve  it  is  well  to  test  with  the  electrode  at  various 
points  on  the  nerve  trunk,  both  above  and  below  the  scar  as  well  as  at  diff- 
erent points  within  the  scar.  In  all  nerve  scars  an  attempt  should  be  made 
to  indentify  intact  branches  by  the  electrode  so  as  to  avoid  injuring  them  in 
freeing  the  nerve.  Not  infrequently  nerve  branches  may  pass  through  sur- 
rounding scar  without  being  sufficiently  compressed  by  the  scar  to  cause 
physiological  interruption  and  may,  therefore,  be  identified  by  the  electrical 
current.  When  the  branches  do  not  transmit  impulses  identification  by  the 
electrode  obviously  is  not  possible,  and  greater  difficulty  is  encountered  re- 
quiring greater  care  in  the  process  of  dissection.  Tn  following  the  nerve  from, 
above  and  below  the  delicate  branches  to  adjacent  muscles  must  be  safeguarded. 
This  factor,  together  with  the  close  proximity  to  large  vessels,  compels  the 
surgeon  to  advance  slowly  and  with  extreme  caution. 

The  nerve  may  be  retracted  conveniently  by  passing  moist  tapes,  about 
r  cm.  wide,  around  the  nerves,  beginning  on  the  side  on  which  there  are  either 
large  vessels,  nerves  or  important  branches;  thus  by  keeping  these  always  in 
view,  including  them  can  be  avoided.  The  ends  of  the  tapes  are  clamped  with 
artery  forceps,  the  weight  of  which  may  suffice  to  hold  the  nerve  in  position 
without  injury. 

The  knife  should  be  changed  frecjuently  while  dissecting  through  the  scar. 


I40         SURGICAL    AND     MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

SO  as  to  have  at  all  times  one  that  is  sharp.  The  scar  is  often  penetrated  by- 
stray  neuraxes  which  seem  to  give  to  nerve  scar  a  consistency  denser  and  harder 
than  other  scar,  owing,  possibly,  to  the  presence  of  neurokeratin.  On  cutting 
such  a  scar  a  peculiar  scraping  noise  is  recognized  which  speaks  for  the  scar 
density.     Hence  the  need  of  a  knife  always  sharp. 

The  deep  scar  should  be  excised,  when  feasible,  but  this  frequently  is  not 
possible.  Instead,  after  the  nerve  has  been  freed,  the  scar  may  be  infolded 
on  itself  and  sutured.  In  this  manner  a  smooth  bed  may  be  made,  new  scar 
formation  avoided  and  troublesome  hemorrhage  from  scar  circumvented. 
When  a  smooth  bed  for  the  nerve  cannot  thus  be  made,  either  a  small  muscle 
belly — not  a  cut  and  raw  muscle  surface,  which  only  increases  scar  formation — 
may  be  sutured  so  as  to  form,  by  its  fascial  covering  a  smooth  surface  for  the 
nerve;  or  a  fatty  flap  may  be  passed  under  the  nerve.  A  free  fatty  trans- 
plant will  tend  to  form  scar  and  should  be  avoided.  Care  should  be  taken 
to  suture  the  fatty  flap  to  adjacent  tissues  on  both  sides  of  the  nerve  in  order 
that  constriction  about  the  nerve  may  be  prevented.  Generally  speaking, 
if  the  line  of  nerve  suture  has  been  made  so  as  to  obtain  epineural  approxi- 
mation, no  other  protection  of  the  nerve  trunk  is  necessary.  If  further  pro- 
tection be  desired,  a  layer  of  Ruber's  modified  cargile  membrane  may  be 
passed  about  the  nerve.  This  causes  no  scar  tissue  reaction,  and  remains 
undisturbed  for  a  period  of  months,  whereas  ordinary  cargile  is  about  as  readily 
absorbed  as  catgut  and,  therefore,  of  little  service. 

Owing  to  the  length  of  most  nerve  operations  the  field  should  be  protected 
more  than  is  usual  in  shorter  operations.  For  this  purpose,  moist  cotton  pads 
about  6  by  8  inches  may  be  used.  They  are  carefully  placed  so  as  to  lie 
smooth  and  cover  all  of  the  field  except  in  the  direct  line  of  the  nerve.  Being 
wet  they  stay  in  place,  are  smooth,  and  facilitate  handling  the  delicate  and 
fine  sutures  used  in  nerve  surgery.  Sutures  are  easily  picked  off  the  cotton, 
remain  in  place  and  being  black  they  stand  out  in  contrast  against  the  white 
background  of  the  cotton.  Furthermore,  at  the  end  of  the  operation  the  underly- 
ing tissues,  as  a  result  of  being  covered  constantly  with  moist  cotton,  are  not 
traumatized  or  dried,  and  appear  as  fresh  as  when  first  incised.  When  such 
pads  are  not  used,  the  threads  are  often  hard  to  find  in  the  tissues  and  may 
adhere  to  them. 

Constant  irrigation  is  maintained  with  salt  solution,  i:)articularly  when 
the  nerve  ends  are  cut  and  during  the  time  they  are  being  sutured.  This 
helps  to  arrest  oozing  from  the  scar  tissues  and  bleeding  from  the  nerve  ends, 


TECHNIC  OF  NERVE  SUTURE  141 

and  avoids  trauma  connected  with  sponging.  If  sponges  are  used  they  should 
be  small  bits  of  moist  cotton  held  in  forceps  and  placed  over  the  nerve  ends. 
If  the  bleeding  is  more  profuse,  bits  of  torn  muscle  held  over  the  bleeding 
points  will  be  found  useful,  or  the  nerve  may  be  held  between  the  lingers  for 
a  few  moments  using  gentle  pressure. 

The  surgeon  should  palpate  the  whole  of  the  nerve  trunk  exposed  in  the 
field,  not  only  the  ner\-e  scar  but  the  normal  nerve  as  well.  Electrodes  should 
again  be  applied  and  each  response  carefully  noted  both  by  inspection  and 
palpation.  Occasionally,  a  response  not  seen  may  be  appreciated  by  pal- 
pation. It  must  be  remembered  that  even  though  no  response  results,  this 
cannot  always  be  interpreted  to  mean  that  neuraxes  have  not  penetrated 
the  scar  and  passed  into  the  distal  stump.  Although  they  have  passed  the 
scar,  they  may  not  yet  have  reached  their  ultimate  destination  within  the 
muscle ;  or,  having  gained  the  muscle,  they  may  not  yet  have  formed  the  motor 
end  plates.  (See  Figs.  44-48.)  Hence  a  negative  response  does  not  always 
imply  failure  of  downgrowth.  In  the  decision  to  excise  a  part  of  the  nerve 
the  whole  clinical  ensemble  as  well  as  the  anatomical  appearance  of  the  nerve 
must  be  taken  into  consideration. 

Special  Incisions. — For  exposure  of  some  of  the  nerves,  special  incisions 
other  than  those  which  follow  the  usual  anatomical  course  of  the  nerve  are  to 
be  preferred.  This  is  particularly  true  of  the  musculospiral  nerve,  the  pos- 
terior interosseous  and  the  sciatic.  These  incisions  will  be  discussed  in  detail 
under  the  chapter  dealing  with  each  nerve. 

The  skin  incision  should  be  made  sufficiently  long  to  enable  free  exposure 
of  the  nerve  both  above  and  below  the  scar.  A  small  incision  delays  the  opera- 
tion and  in  the  end  generally  requires  lengthening.  Secondary  enlargement 
of  the  field  entails  a  waste  of  time,  and  is  rarely  as  neatly  accomplished  as  if 
the  incision  had  been  made  long  enough  in  the  first  instance.  At  times  it  is 
not  possible  to  foretell  the  required  length,  particularly  if  transposition  of 
the  nerve  becomes  necessary,  so  that  in  these  cases  secondary  enlargement 
cannot  be  avoided. 

Use  of  Tourniquet. — A  tourniquet  should  not  be  used  because  each 
bleeding  point  should  be  dealt  with  individually,  and  this  cannot  be  done 
satisfactorily  if  a  tourniquet  has  been  applied.  Unless  hemostasis  is  nearly 
complete  in  a  wound  in  which  scar  tissue  is  present,  an  increase  in  the  scar 
results,  due  perhaps  to  the  stimulus  of  the  fibrin  in  the  blood  clot  to  the 
fibroblast.     However,  in  a  few  positions,  such  as  at  the  wrist,  in  the  hand  and 


142         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

in  the  sole  of  the  foot,  the  tourniquet  applied  above  these  levels,  while  not 
indispensable,  is  a  great  help,  for  in  the  resulting  bloodless  field,  structures 
anatomically  similar  may  be  readily  differentiated  from  nerves  and  more 
accurate  nerve  surgery  done.  When  the  tourniquet  is  used  each  blood  vessel 
encountered  should  be  clamped  above  and  below  before  cutting,  and  immedi- 
ately tied.  Many  vessels  may  be  recognized  in  the  field,  and  in  this  man- 
ner the  the  amount  of  bleeding,  after  removal  of  the  tourniquet,  can  be 
diminished.  If  care  has  been  taken  to  tie  each  vessel,  the  only  bleeding  left  is 
that  from  the  scar  and  capillary  oozing  for  which  there  is  little  that  the  sur- 
geon can  do.  For  such  bleeding  coaptation  of  the  raw  edges  of  the  tissues 
of  the  wound  is  the  best  form  of  hemostasis.  It  has  been  my  practice  hi  these 
cases  to  close  the  wound  in  layers  and  apply  a  pressure  bandage  before  com- 
pletely removing  the  tourniquet.  In  this  manner  better  hemostasis  is  obtained, 
providing  the  vessels  have  been  tied  as  they  have  been  encountered. 

Nerve  Stretching. — After  the  nerve  has  been  freed  from  the  immediate 
scar,  it  can  be  liberated  from  contiguous  parts  by  gentle  traction.  This  is 
best  done  before  excising  the  intervening  scar,  and  admits  of  using  the  scar 
to  make  traction,  thus  avoiding  additional  trauma  to  the  nerve  trunk  or  nerve 
ends,  particularly  after  the  nerve  ends  have  been  prepared  for  suture.  Squeez- 
ing the  nerve  ends  to  make  traction  must   be  avoided. 

Rotation  of  the  Nerve  Trunk. — To  avoid  axial  rotation  of  the  nerve  trunk 
when  suturing  identification  sutures  should  be  passed  on  both  the  central  and 
distal  parts  of  the  nerve  before  its  normal  relations  are  disturbed.  Silk 
sutures  are  passed  through  the  epineurium  in  the  same  corresponding  plane  on 
both  the  medial  and  lateral  sides  of  the  nerve  trunk  above  and  below  the  level 
of  the  injury.  Then  when  the  lateral  sutures  and  the  medial  sutures  are 
brought  in  alignment  corresponding  points  of  the  nerve  circumference  are 
brought  together  without  rotation.  To  distinguish  the  medial  from  the 
lateral  border  white  silk  sutures  may  be  used  on  one  side  and  black  silk  on 
the  other. 

In  place  of  identification  sutures  mosquito  forceps  may  be  used  to  grasp 
the  epineurium  on  the  lateral  and  medial  margins  of  the  nerve.  However, 
these  are  liable  to  come  off  if  only  the  epineurium  is  grasped,  and  more  of  the 
nerve  should  not  be  included  in  the  bite  of  the  forceps.  Another  method  to 
avoid  rotation  in  suturing  is  to  approximate  similar  appearing  nerve  bundles; 
but  this  method  is  unreliable  since  after  loss  of  nerve  substance  bundles  corre- 
sponding in  appearance  may  have  a  totally  different  function.     Surface  mark- 


TECHNIC  OF  NERVE  SUTURE  I43 

ings  and  striations  of  the  nerve  trunk  are  of  little  \aluc  where  there  has  been  a 
loss  of  ner\T  substance. 

Level  of  Suture. — In  determining  the  level  of  the  suture  it  is  best  to  cut 
only  partially  through  the  nerve  trunk  inspecting  the  cross  sections  as  they 
present  at  each  successive  level,  and  thus  determine  by  the  appearance  of  the 
funiculi  the  proper  level  of  suture.  (See  Fig.  50.)  An  ordinary  large  library 
magnifying  glass  can  be  sterilized  and  used  to  bring  out  the  finer  details  of  each 
cross  area. 

In  liberating  or  cutting  the  nerve  forceps  should  be  placed  not  on  the  sound 
part  of  the  nerve  but  on  the  epineurium  or  scar  of  the  bulb.  Three  mosquito 
forceps  taking  only  a  fine  bite  are  used,  one  on  either  side  of  the  nerve  bull) 
and  a  third  at  the  end.  Gentle  traction  is  made  to  steady  the  nerve  so  as  to 
permit  of  clean  transverse  sections.  If  the  nerve  is  not  properly  held  it  tends 
to  rotate  on  cutting  and  a  ragged  uneven  surface  results. 

As  long  as  there  is  scar  between  the  funiculi  and  these  do  not  appear  as 
distinct  bundles,  another  level  must  be  sought.  Distinct  funicular  bundles 
must  be  obtained.  When  the  incision  is  carried  through  sound  nerve  tissue  the 
bundles  stand  out  sharply  without  scar  tissue  between  them,  and  the  ej^ineurium 
tends  to  retract,  leaving  the  bundles  as  prominent  points  on  the  cut  surface. 
When  sound  nerve  tissue  is  reached,  free  bleeding  occurs  and  generally  from  one 
or  two  points,  rather  than  the  slight  oozing  from  the  entire  surface  which  is 
seen  when  scar  tissue  is  still  present. 

The  end  bulb  of  the  central  stump  is  made  up  of  regenerating  neuraxes, 
proliferating  sheath  cells  and  connective  tissue.  (See  Fig.  216.)  The  neura.xes 
are  interlaced  with  numerous  branchings  and  end  discs,  and  distinct  funicular 
arrangement  with  fibers  in  parallel  bundles  is  usually  not  found  until  the 
neck  of  the  bulb  is  reached.  On  the  distal  end,  the  bulb  consists  only  of 
a  small  connective  tissue  cap  without  neuraxes.  Scar-free  tubules  are  found 
after  one  or  two  thin  sections  are  made,  without  cutting  far  into  the 
nerve.  Rarely  more  than  5  mm.  is  excised  to  obtain  a  good  cross  area  in  the 
<listal  end. 

If  a  nerve  bulb  is  found  with  the  nerve  trunk  continuity  maintained  and 
excision  is  determined,  the  bulbous  part  of  the  nerve  is  held  with  three  mosquito 
forceps  as  indicated  above  and  successive  incisions  are  made.  These  should 
be  begun  in  the  central  part  of  the  bulb  and  gradually  continued  first  toward 
the  distal  and  then  toward  the  central  end  until  good  cross  areas  are  obtained 
both  abo\e  and  lielow. 


144         SURGICAL   AND    MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 

By  cutting  incompletely  through  the  nerve  at  each  incision  there  is  less 
manipulation  and  less  trauma  to  the  nerve  ends.  It  is  also  easier  to  suture 
when  the  nerve  ends  are  not  completely  free  and  there  is  less  tendency  to  axial 


Fig.  50. — Nerve  with  scar  to  be  excised.  Illustrate?  method  of  using  scar  as  means  of  fixation 
of  nerve  ends,  permitting  greater  accuracy  and  facility  in  suturing,  (i)  By  passing  needle  obliquely 
suture  is  less  apt  to  tear  out.  Stay  suture  helps  to  prevent  axial  rotation  and  can  be  withdrawn 
when  other  sutures  are  tied.  Note  consecutive  partial  incisions  through  scar  until  normal  appearing 
funiculi  are  reached.     (Stookey,  Surg.,  Gyn.  and  Obst.,  1918.) 

rotation  when  anatomical  continuity  is  still  maintained .  Thus  greater  accuracy 
is  gained  in  placing  the  nerve  sutures  and  the  nerve  pattern  is  less  disturbed. 
(See  Fig.  50.) 

In  some  instances  the  nerve  bulb  may  involve  only  part  of  the  nerve  trunk 


f^iG.  51.  Fig.  52. 

Figs.  51  and  52. — Partial  suture  of  the  sciatic  in  injury  of  the  peroneal  division.     The  nerve 

is  first  mobilized  and  consecutive  incisions  are  made  until  normal  appearing  funiculi  are  reached. 

A  longitudinal  incision  is  then  cleanly  made  to  separate  the  scar  from  the  sound  nerve.     The  nerve 

ends  are  then  sutured  in  the  usual  manner  without  tension.     (Stookey,  Surg.,  Gyn.  and  Obst.,  1918.) 


and  only  partial  section  of  the  nerve  be  indicated.  In  making  such  an  excision 
the  bulb  is  grasped  in  the  same  manner  as  for  any  bulb,  care  being  taken  to 
protect  the  sound  part  of  the  nerve.     Sections  are  made  partially  through  the 


TECHNIC  OF  NERVE  SUTURE 


145 


bulb  until  scar-free  cross  areas  are  reached.  When  these  levels  are  determined 
a  clean  longitudinal  cut  is  made  to  separate  the  bulb  from  the  normal  part  of 
the  nerve  trunk  and  end-to-end  suture  of  the  divided  part  is  then  done.  (See 
Figs.  51,  52,  53,  54  and  55.J 


Fig.  S3. 


Fig.  54. 


Fig.  55. 
Figs.  53,  54,  55. — Perforation  of  sciatic.      Demonstrates  method  of  partial  suture  after  e.xcision  of 
scar  tissue.     Line  of  excision  should  be  sharp,  avoiding  normal  funiculi  as  far  as  possible.     Plain 
catgut  sutures  are  passed  through  and  through  and  tied  after  all  are  in  place.     (Stookey,  Surg., 
Gyn.  and  Obst.,  igi8.) 


Technic  of  End-to-end  Suture. — A  000  plain  catgut  suture  is  passed  on 
each  side  of  the  nerve,  equidistantly  placed,  taking  a  bite  deeper  than  through 
the  epineurium.  While  this  suture  passes  somewhat  within  the  nerve  it  really 
becomes  an  epineural-perineural-epineural  suture;  for  if  a  smooth  needle  is 
used  the  funiculi  are  pushed  aside  and  the  suture  then  lies  between  the  funiculi 
in  the  perineural  connective  tissue  and  hence  does  very  little  harm  to  the  nerve. 
By  these  sutures  the  nerve  is  brought  together  in  its  deeper  parts,  hemorrhage 
between  the  nerve  ends  is  avoided,  diminishing  the  amount  of  scar  and  lessening 


10 


146 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


the  tension  on  the  line  eipneural  sutures.  These  stay  sutures  may  also  serve 
to  prevent  axial  rotation,  particularly  if  they  are  placed  before  complete 
excision  of  the  intervening  nerve  scar  and  while  anatomical  continuity  is  not 


Fig.  56. — Technic  of  end-to-end  suture.  .1,  Two  000  plain  catgut  sutures  on  fine  rounded 
needles  are  passed  through  the  ner\-e  at  opposite  points,  taking  a  bite  a  Uttle  deeper  than  the  epi- 
neurium.  The  sutures  are  then  tied  and  the  ends  clamped  without  cutting.  These  sutures  serve  to 
bring  the  ends  in  alignment  and  as  stay  sutures.  B,  The  two  stay  sutures  are  held  to  steady  the 
nerve  while  the  fine  epineural  sutures  are  passed.  Black  Corticelli  AAA  silk  is  split  into  three 
strands,  waxed  and  then  used  for  the  epineural  sutures.  Each  suture  is  cut  and  tied  after  it  is  passed. 
For  accurate  approximation  of  the  epineural  edges  the  sutures  must  be  tied  unth  forceps.  C,  The  upper 
surfaces  have  been  sutured  and  the  stay  sutures  are  now  reversed,  the  lower  one  passed  beneath  the 
nen'e  and  the  upper  one  over  the  nerve  so  as  to  expose  the  under  surface.  The  under  surfaces  are 
then  sutured  in  the  same  manner  as  the  upper.  D,  The  ends  have  been  brought  together,  the  sutures 
cut  after  being  tied  so  as  to  evert  slightly  the  epineural  edges.     (Stookey,  J.  .\.  M.  A.,  igrg.) 

entirely  broken.  These  sutures  are  tied,  with  ends  about  3  inches  long 
to  which  artery  forceps  are  clamped  thus  holding  the  nerve  firmly  and  facili- 
tating the  passing  of  the  epineural  sutures.     (See  Fig.  56.) 


TECHNIC  OF  NERVE  SUTURE  1 47 

The  silk  epineural  sutures  are  then  passed  on  the  upper  surface  between  the 
two  stay  sutures.  With  very  fine  tooth  forceps  epineurium  only  is  grasped  and 
each  suture  accurately  placed  and  tied  with  forceps  so  that  the  epineural  edge  is 
everted.  If  the  sutures  have  been  correctly  placed,  eversion  of  the  epineurium 
is  easily  accomplished  and  gives  a  smooth  line  of  union  on  its  inner  surface.  Each 
suture  is  cut  as  it  is  tied,  sufficient  sutures  being  used  to  insure  complete  approxi- 
mation— the  number  naturally  depending  on  the  size  of  the  nerve. 

By  reversing  the  two  catgut  sutures,  i.e.,  by  passing  the  one  over  and  the 
other  beneath,  the  under  surface  is  readily  brought  into  view  and  sutured  in 
like  manner. 

The  advantages  of  two  stay  sutures  over  a  single  stay  are  obvious. 
If  a  single  stay  is  used  the  nerve  rotates  as  the  remaining  sutures  are  passed  and 
the  nerve  is  not  so  firmly  held, or  its  under  surface  as  readily  brought  into  view 
When  a  single  stay  suture  is  tied,  the  lateral  edges  of  the  nerve  evert  and 
epineural  approximation  is  then  difficult. 

Hemorrhage  Between  the  Nerve  Ends. — If  the  sutures  have  been  accu- 
rately placed  and  tied  coaptation  of  the  edges  occurs  and  further  hemorrhage  from 
the  nerve  ends  need  not  be  feared.  After  the  stay  sutures  have  been  reversed  the 
open  half  of  the  nerve  yet  to  be  sutured  is  constantly  irrigated  with  warm  salt 
solution  while  the  remaining  epineural  sutures  are  being  passed;  thus  small  clots 
of  blood  are  prevented  from  forming  between  the  nerve  ends.  Blood  clots  will 
not  form  after  the  nerve  has  been  sutured,  providing  the  ends  are  in  apposition. 

A  small  amount  of  connective  tissue  forms  between  the  nerve  ends.  The 
thinner  the  layer  of  connective  tissue,  the  less  resistance  will  the  neuraxes  meet, 
and  the  more  complete  will  be  the  regeneration.  Nageotte  (1918)  recommended 
that  a  small  distance,  approximately  5  mm.,  be  left  between  the  nerve  ends  so 
as  to  allow  for  greater  dispersion  of  the  neuraxes  in  case  the  proper  funiculi  are 
not  brought  exactly  end  on.  By  exact  apposition  without  any  intervening 
space,  Nageotte  holds  that  there  may  be  more  accurate  apposition  of  a  few 
funiculi,  but  nevertheless,  with  considerable  misdirection  of  the  fibers  in  new 
and  foreign  channels.  Whereas,  if  a  short  distance  is  left  between  the  nerve 
ends  greater  dispersion  of  the  nerve  fibers  takes  place  and  the  opportunity  for 
them  to  reach  their  proper  channels  is  more  favorable,  and  downgrowth  in  these 
instances  is  more  uniform.  However,  neurotization  is  not  so  abundant  nor 
early  as  when  the  ends  are  sutured  without  any  intervening  space.  I  have  had 
no  personal  experience,  either  experimentally  or  clinically,  with  this  method 
of  suturing,  but,  judging  from  the  protocols  of  Nageotte's  experiments,  I  do 


148         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

not  think  that  sufficient  evidence  is  offered  to  warrant  the  conclusion  which  is 
reached.  It  seems  to  me  that  the  possibility  of  hemorrhage  between  the  nerve 
ends  and  resulting  thick  scar  when  ends  are  not  brought  in  close  contact  is  a 
disadvantage  which  more  than  offsets  the  theoretical  advantage  presumably 
gained.  The  thinner  the  layer  of  intervening  scar  the  less  the  resistance  to  the 
neura.xes.  Furthermore  there  is  no  evidence  to  indicate  that  at  the  point 
of  suture  there  is  any  chemotactic  or  other  influence  to  determine  a  selective 
downgrowth  of  neura.xes  which  would  attract  each  group  into  its  proper  sheath. 
There  may  be  a  general  attraction  at  the  point  of  suture  but  not  a  particular 
attraction  for  particular  groups  of  neuraxes. 

In  the  presence  of  a  small  nerve  defect,  end-to-end  suture  may  be  accom- 
plished by  slight  stretching,  or  by  transposition  of  the  nerve  and  by  altering 
the  position  of  the  limb.  As  has  already  been  pointed  out,  nerve  stretching 
should  be  done  with  considerable  caution,  since  the  distance  gained  can  be 
accomplished  only  by  taking  up  the  normal  laxity  of  the  nerve  trunk  in  its 
contiguous  parts,  or  if  carried  farther  by  multiple  tears  within  the  nerve  trunk, 
or  by  evulsion  from  the  spinal  cord. 

Transposition  of  the  nerve  may  permit  defects  to  be  overcome  which  might 
otherwise  prevent  end-to-end  suture.  A  nerve  may  be  freed  and  raised  out 
of  its  bed  over  quite  a  distance  without  interfering  with  its  nutrition  or 
its  conductivity.  In  transposing,  care  must  be  taken,  so  far  as  possible, 
to  safeguard  nerve  twigs  and  prevent  the  formation  of  sharp  angles  or 
kinks. 

Technic  of  Nerve  Crossing. — Technic  of  nerve  crossing  requires  no  special 
description  other  than  that  given  for  end-to-end  suture.  The  distal  nerve 
is  brought  up  to  the  central  nerve  trunk  to  which  it  is  to  be  united,  to  determine 
the  exact  point  at  which  the  nerve  should  be  severed,  with  sufficient  allowance 
for  retraction  so  as  to  permit  union  without  tension  on  the  line  of  suture.  When 
the  level  at  which  the  distal  nerve  is  to  be  cut  is  decided,  two  catgut  stay  sutures 
should  be  passed  before  cutting;  this  thus  permits  placing  of  the  suture  more 
accurately  and  with  less  trauma  to  the  nerve  ends  than  can  be  done  if  the 
severed  nerve  lies  free  in  the  wound.  Likewise,  whenever  possible,  the  same 
sutures  may  be  passed  through  the  central  nerve  before  it  is  cut.  Care  must  be 
taken  to  make  sure  that  no  kinks  or  angles  shall  result  following  the  suture, 
such  as  may  occur  when  the  nerve  is  hooked  around  a  muscle,  and  due  allowance 
must  be  made  for  the  normal  contractions  of  muscles  and  movements  of  the 
parts. 


TECHNIC  OF  NERVE  SUTURE 


I4Q 


Partial  Nerve  Crossing.— After  determining  the  level  and  the  thickness 
of  the  partial  nerve  segment  which  is  to  be  raised,  two  fine  silk  sutures  are 
placed  at  this  point,  then  a  thin,  narrow,  sharp  knife  is  inserted  in  the  nerve  at 
the  point  to  obtain  exactly  the  required  thickness,  and  the  incision  is  carried 
upward  the  desired  length.  So  far  as  possible,  the  longitudinal  part  of  the 
incision   is   made  between   funiculi   which  may  in   some   instances   be   recog- 


FiG.  57. — Schematic  drawing  showing  technic  of  partial  nerve  crossing.  When  the  point 
at  which  the  nerve  is  to  be  cut  is  determined  and  the  length  of  the  fiap  estimated,  the  sutures  are 
passed  before  making  the  flap  or  cutting  the  nerve  to  be  neurotized.  Thus  sutures  are  placed  without 
manipulating  the  nerve  ends  and  crushing  them  with  forceps. 

nized  by  rolling  the  nerve  between  the  lingers.  In  order  to  avoid  possible  injury 
to  the  remaining  nerve  trunk  the  transverse  incision  which  frees  the  flap  is  made 
from  within  out.  The  figures  (Fig.  57)  illustrate  better  than  description  could 
the  points  of  technic  for  l)oth  partial  and  complete  nerve  croning. 

Technic  of  Nerve  Graft. — The  technic  of  the  graft  is  so  exacting  that  unless 
done  by  those  having  considerable  practice  the  results  may  be  disappointing. 
The  utmost  regard  for  minute  points  of  technic  is  essential.     Success  depends 


150         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

in  a  great  measure  on  the  accuracy  with  which  the  grafts  are  brought  end  on 
and  in  precise  contact  with  the  cross  areas  of  both  the  central  and  distal  stumps. 
If  the  sutures  are  not  correctly  placed,  or  not  tied  with  just  the  proper  tension, 
the  nerve  ends  are  likely  to  be  turned  aside  and  in  place  of  the  graft  being  end  on, 
it  may  be  turned  so  that  its  lateral  surface  lies  against  the  central  cross  area. 
(See  Fig.  58.)  While  neuraxes  may  grow  into  the  graft,  the  probability  of  such 
penetration  is  greatly  diminished  by  faulty  approximation.  For  these  reasons, 
the  individual  technic  must  be  considered  in  estimating  the  ultimate  value  of 
the  graft,  for  it  plays  a  predominating  role. 


Fig.  58. — Why  downgrowth  may  not  take  place  in  a  graft.     Such  apposition  as  shown  here  may 
occur  if  the  sutures  are  not  properly  placed  or  properly  tied.     End-to-end  apposition  must  be  obtained. 

A  sufficient  number  of  grafts  should  be  taken  to  cover  the  cross  area  of  the 
central  and  distal  stumps.  Unless  this  is  done,  many  central  neuraxes,  having 
no  path  down  which  they  can  grow,  may  become  lost,  though  Huber  (191 9) 
has  shown  that  a  few  are  able  to  penetrate,  growing  as  far  as  the  distal  stump  in 
the  small  connective  tissue  spaces  between  the  nerve  transplants.  The  aim 
of  the  surgeon  should  be  to  connect  each  funiculus  with  a  graft.  This  may  be 
accomplished  by  suturing  each  graft  separately  in  the  desired  position  thus  to 
establish  the  central  and  distal  connections  with  precision.  In  some  of  the 
nerves  in  which  the  funiculi  are  numerous,  or  at  certain  levels  in  others  where 
the  larger  funiculi,  have  been  broken  up  into  many  smaller  ones,  this  is  often 
not  possible;  nevertheless,  the  attempt  should  be  made. 

Technic  of  the  Graft.  Author's  Method. — When  the  nerve  to  be  grafted 
is  freed  from  the  scar  tissue  and  the  nerve  ends  successively  incised  until  a 
satisfactory  cross  area  is  obtained  one  or  two  stay  sutures  are  passed  at  the 
proper  level,  before  the  nerve  continuity  is  completely  severed,  so  as  to  hold  the 
nerve  in  alignment,  prevent  rotation,  and  help  in  fixation  of  the  nerve  ends 
during  suture.  These  stay  sutures  need  not  be  tied  but  each  end  may  be 
clamped  near  its  exit  from  the  nerve. 

The  distance  to  be  bridged  is  then  accurately  measured  with  a  centimeter 
divider. 

A  skin  nerve,  such  as  the  radialis  or  the  external  saphenous  on  the  dorsum 
of  the  leg,  may  be  used.  In  order  to  save  time  another  operating  team  may 
lay  bare  the  skin  nerve.     Preferably  a  degenerated  nerve  should  not  be  used. 


TECHNIC  OF  NERVE  SUTURE 


151 


such  as  one  would  find  in  the  leg  on  the  side  of  a  sciatic  nerve  injury.  The 
sheath  cells  in  such  a  nerve  are  no  longer  in  active  proliferation;  there  may 
also  be  some  increase  in  connective  tissue,  particularly  if  the  injury  to  the 
parent  nerve  is  of  some  standing.  It  is  possible  that  whatever  of  neurotropism  ■ 
there  may  be  is  diminished  in  such  a  nerve  as  compared  with  a  fresh  transplant. 
However,  this  is  of  academic  interest  rather  than  of  real  importance.  In 
view  of  the  downgrowth  of  neuraxes  in  preserved  specimens,  one  must  question 
the  value  of  the  role  imputed  to  neurotropism. 

The  skin  nerve  having  been  laid  bare  over  the  desired  length,  fine  waxed 
silk  sutures  on  fine  curved  or  straight,  smooth  needles  are  passed  at  an  interval 
equal  to  the  distance  to  be  bridged,  as  previously  measured.     (See  Fig.  59.) 


J 


i] 


J) 


i 


J) 


Fig.  59. — Technic  of  nerve  graft.  The  skin  nerve  to  be  used  is  laid  bare,  and  the  length  of 
the  nerve  segments  to  be  used  being  measured  ofT,  fine  waxed  silk  sutures  on  fine  round  curved  needles 
or  arterial  needles  are  passed  leaving  sufficient  margin  to  cut  between  sutures.  The  sutures  should 
be  of  equal  length  and  passed  all  in  one  direction.  The  nerve  segments  are  then  cut  with  a  thin 
sharp  knife. 


A  small  margin  is  allowed  for  cutting  the  nerve  segments. 

The  sutures  are  all  passed  in  one  direction,  the  nerve  being  held  tense 
by  small  forceps  either  central  or  distal  to  the  grafts.  Under  no  circum- 
stances should  the  nerve  segments  to  be  used  in  the  graft  be  held  by  forceps, 

The  sutures  are  then  curled  carefully  so  as  to  prevent  entanglement, 
the  needles  all  on  one  side  and  the  free  ends  on  the  other. 

The  nerve  segments  are  cut  with  a  sharp,  thin  knife,  avoiding  crushing 
the  nerve  ends. 

Each  segment  is  then  picked  up  by  covering  it  with  a  smooth,  moist 
cotton  pad.  (See  Fig.  60. j  If  the  cotton  is  carefully  placed  over  the  nerve 
and  sutures,  they  adhere  to  the  moist  cotton  and  each  segment  may  thus  be 
lifted  from  the  wound  and  placed  in  the  operative  field  without  handling. 
(See  Fig.  61.) 


152  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

By  folding  the  cotton  pad  so  that  its  free  border  is  parallel  to  the  trans- 


Fio.  60. — Technic  of  nerve  graft.  The  threads  are  curled  to  avoid  tangling.  A  moist  cotton 
pad,  the  length  of  the  nerve  segment,  is  placed  over  each  transplant.  The  transplant  and  sutures 
adhere  to  the  cotton  and  can  be  picked  up  without  handling  or  danger  of  pulling  out  the  sutures. 
The  segment  can  be  carried  from  one  field  to  the  other  without  danger  of  dropping. 


Fig.   61. — Technic 


graft.     Transplant    picked    up    on  moist  cotton  and  ready  to  be 
carried  into  the  nerve  defect. 


Fig.  62. — Technic  of  nerve  graft.  Transplant  in  place  ready  for  suture.  .'\  stay  suture  is 
passed  through  the  nerve  trunk  to  fix  its  ends  during  suture.  In  place  of  tying  this  suture  each  end 
may  be  clamped  close  to  the  nerve. 


plant,  the  latter  may  be  placed  between  the  nerve  ends  so  as  to  be  in  exact 
position  for  suture.     (See  Figs.  62  and  6,5.) 


TECHNIC  OF  NERVE  SUTURE  1 53 

By  means  of  the  cotton  pad  neither  the  nerve  nor  the  sutures  are  handled, 
the  latter  do  not  become  entangled,  the  danger  of  pulling  out  the  sutures  is 
eliminated,  and  the  nerve  may  be  maneuvered  into  its  proper  position  for  suture 
with  the  least  trauma.  A  small  stream  of  salt  solution  will  be  found  helpful 
in  flooding  the  nerve  off  the  cotton.  During  the  process  of  suture  the  nerve 
is  irrigated  with  warm  salt  solution,  thus  creating  a  clear  field,  thereby  aiding 
in    accurate   funicular  approximation   of    the   graft.     In    this    manner,    each 


Fig.  63. — Technic  of  nerve  graft.  One  transplant  sutured  and  a  second  in  place  ready  for 
suture.  The  under  part  of  the  defect  is  bridged  first,  unless  important  motor  funiculi  can  be  identified 
when  these  are  sutures  first. 

transplant  is  sutured  separately,  both  distally  and  centrally,  with  whichever 
funiculus  desired.     The  sutures  must  be  tied  with  forceps  and  cut  short. 

The  accuracy  of  the  graft  depends  in  a  measure  on  the  correct  placing  of 
the  sutures,  the  e.xact  amount  of  tension  in  tying,  and  dehcate  manipulation 
by  meajis  of  the  sutures  during  the  process  of  tying.     (See  Fig.  64). 


Fig.  64. — Technic   of   nerve   graft.     Cable    transplant   in   place.     (Stookey,    J.  .^.  M.  A.,    igig.) 

Elsberg's  Method. — In  place  of  suturing  each  graft  separately  Elsberg 
(1919)  has  devised  a  very  ingenuous  and  skillful  method  which  permits  suturing 
the  entire  cable  graft  en  masse,  thus  saving  considerable  time  and  reducing 
the  handling  of  the  graft  to  a  minimum.     (See  Fig.  65.) 

"After  having  determined  the  length  of  the  defect  which  is  to  be  bridged 
over  by  the  graft,  and  the  number  of  strands  that  will  be  required,  one  or 
several  cutaneous  nerves  are  exposed  and  carefully  dissected  out  until  they 
remain  attached  only  at  their  upper  and  lower  ends.  Two  sutures  are  then 
passed    in'  and  out  of  the  nerve  at  measured  distances.     For  the  sake  of  de- 


154         SURGICAL   AND   MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 


scription,  let  us  say  that  the  graft  is  to  be  7  cm.  long  and  is  to  consist  of  three 
strands.  The  one  suture  (A)  is  passed  through  near  the  attached  upper  end 
of  the  freed  nerve,  from  the  inner  to  the  outer  side  of  the  nerve;  a  loop  is  left 
loose  and  the  needle  is  then  passed  through  the  nerve  from  the  outer  to  the 
inner  side  a  Httle  more  than  7  cm.  from  the  first  point;  again  a  loop  is  left,  and 
the  needle  passed  through  the  nerve,  from  its  inner  to  its  outer  side,  at  the  same 


^ 


t-   -r 


Fig.  65. — The  cable  graft.  .-1,  The  bulb  resected  and  ends  of  nerves  e.xposed;  B,  the  sutures 
passed  through  the  cutaneous  nerve  used  from  cable  graft;  C,  the  nerve  divided  into  segments; 
/),  the  cable  graft  ready  for  transplantation;  £,  the  sutures  passed  through  ends  of  cable  graft  and 
ends  of  nerve;  F,  the  sutures  tied;  G,  the  perineural  sutures  tied.     (Elsberg,  J.  A.  M.  A.,  igig.) 

distance  from  the  last  point.  The  needle  is  then  laid  aside  and  a  second 
needle  and  suture  taken.  This  needle  (B)  is  passed  through  the  lower  end 
of  the  nerve,  from  its  outer  to  its  inner  side,  a  little  more  than  7  cm.  from  the 
point  of  emergence  of  needle  A.  A  loop  of  the  suture  is  left  and  the  needle 
passed  through  the  nerve,  from  the  inner  to  the  outer  side,  at  a  point  3  mm. 
above  the  point  of  emergence  of  suture  A;  finally,  the  needle  is  passed  through 
the  nerve,  from  its  outer  to  its  inner  side,  3  mm.  proximal  to  the  next  point 
above.  The  points  at  which  the  suture  A  has  passed  through  the  nerve 
correspond  to  the  upper  ends  of  the  graft;  and  the  points  through  which  needle 
and  suture  B  have  been  passed  correspond  to  what  are  to  be  the  lower  ends 


TECHNIC  OF  NERVE  SUTURE  1 55 

of  the  strands.  After  the  loops  have  been  carefully  arranged,  the  nerve  is 
cut  with  fine  scissors  or  a  fine  scalpel:  (i)  i  mm.  above  the  beginning  of  A  (2) 
I  mm.  below  the  beginning  of  B  and  (3)  between  each  two  points  through  which 
sutures  A  and  B  are  passed,  apart  in  the  nerve.  An  assistant  then  grasps  the 
two  ends  of  suture  A  and  the  operator  the  two  ends  of  suture  B.  When  trac- 
tion is  made,  the  strands  are  drawn  together.  Then  each  suture  is  loosely 
tied.  A  brings  all  of  the  upper  ends  of  the  strands  together;  B  brings  all  the 
lower  ends  together. 

"After  the  cable  graft  has  thus  been  made,  it  is  transferred  to  its  place 
between  the  divided  ends  of  the  main  nerve  and  sutured  in  position,  according 
to  the  method  shown  in  Fig.  65." 

Thus  from  a  technical  standpoint  to  obtain  successful  regeneration,  not 
only  in  nerve  graft  but  also  in  end-to-end  suture,  an  entire  set  of  exacting 
conditions  must  be  attained  during  the  operation  while  failure  in  any  one  may 
seriously  jeopardize  the  end  results. 

REFERENCES 

Delageniere,  H.:  Traitement  chirurgical  des  blessures  des  nerfs   .    .    .    245  cas  de  sutures 
et  118  liberations  suivies  par  le  Dr.  Tinel,  Bull,  et  mem.  Soc.  de  chir.  de  Par.,  v.  44: 

1918,  524. 

Elsberg,  C.  a.:  Technic  of  nerve  suture  and  nerve  grafting,  J.  A.  M.  A.,  v.  73:  Nov.  8, 

1919,  pp.  1422-1427. 

Elsberg,   C.  A.   and  Woods,  A.  H.:  Problems  in  diagnosis  and  treatment  of  injuries  to 

the  peripheral  nerves,  Arch.,  Neurol.  &  Psychiat.,  v.  2:  1919,  p.  645. 
Frazier,  C.  H.:  Surgical  problems  in  the  reconstruction  of  peripheral  nerves,  Ann.  Surg., 

V.  71 :  Jan.,  1920,  p.  i. 
Frazier,  C.  H.  and  Silbert,  S.:  Five  hundred  cases  of  injuries  of  peripheral  nerves  at  U.  S. 

Army  General  Hospital,  No.  11,  Surg.,  Gynec.  &  Obst.,  v.  30:  Jan.,  1920,  p.  50. 
Gebele:  Zur  Chirurgie  der  peripheren  Nervenverletzungen,    Munchen.    med.  Wchnschr., 

V.  64:   1917,  p.  956. 
Hesnard,    a.:  Notes   de   chirurgie  nervcuse  de  guerre,   Arch,   de  med.  et  pharm.,  Nav. 

1920,  p.  201. 

Hesnard,  A.:  Chirurgie  des  blessures  des  nerfs  peripheriques,  J.  de  med.  de  Bordeaux,  v. 

48:  1918,  p.  S3. 
Huber,    G.    C:  Transplantation  of  peripheral  nerves,  Arch.,   Neurol.  &  Psychiat.,  v.  2: 

1919,  p.  466. 

Huber,   G.   C.:  Repair  of  peripheral  nerve  injuries,  Surg.,  Gynec.  &  Obstet.,  v.  30:  May, 

1920,  p  464. 

Meige,  H.  et  al:  Sutures  nerveuses,  Rev.  neuroL,  v.  25:  pt.  i,  1918,  p.  262. 


IS6         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Nageotte,  J.:  Sur  une  atrophie  musculaire  reflexe  precoce  apres  suture  rles  nerfs  par  affron- 

tenient  et  sur  les  inconvenients  de  la  greffe  nerveuse  vivaiite  auloplastique,  Compt. 

rend.  Soc.  de  bioL,  v.  8i:  July,  20,  1918,  p.  761. 
Perthes:  tjber  dase  lektrische  Verhalten  von  Muskeln  nach  Durch  Trennung  der  zugeho- 

rigen  Nerven,  Miinchen.  med.  Wchnschr.,  v.  66:  1919,  p.  1016. 
Perthes:  Beobachtungen   bei   clcklrischer  Reizung  freigelegter  verletzter  Nerven  im\'er- 

gleich  mit  dem  neurologischen  und  histologischen  Befunde,  Deutsch.  med.  Wchnschr., 

V.  45:  igi9,  p.  897. 
S.4RGENT,  P.  and  Greenfield,  J.   G.:  An  experimental  investigation  of  certain  materials 

used  for  nerve  suture,  Brit.  M.  J.,  v.  2:  pt.  i,  1919,  p.  407. 
Seyberth,   W.:  Ueber   Nervenoperationen   und   ihre   Enderfolge,    Berl.    klin.    Wchnschr. 

V.  55:  1918,  p.  996. 
.SouTTAR,   H.  S.:  Injuries  of  the  peripheral    nerves  from  the  surgical  standpoint,  Brit.  J. 

Surg.,  V.  6:   1918,  p.  279. 
Stiles,  H.  J.:  Operative  treatment  of  nerve  injuries,  Am.  J.  Orthop.  Surg.,  v.  16:   1918, 

P-  351- 
Stoffel,  a.  :  Ueber  die  Schicksale  der  Nervenverletzungen,  besonders  der  Xervenoperierten, 

Miinchen.  med.  Wchnschr.,  v.  64:  1917,  p.  1515. 
Taylor,  A.  and  Boorstein,  S.  W.:  Peripheral  nerve  suture,  Med.  Rec,  v.  95:  1919.  p.  344 


CHAPTER  VIII 

INDICATIONS  FOR  OPERATION    THE  TIME  TO  OPERATE  AND  CAUSES 

OF  FAILURE 

Indications  for  operation  on  peripheral  nerves  depend  upon  a  number  of 
factors  of  which  the  most  important  are  the  history  of  the  case,  the  local  examina- 
tion as  well  as  the  sensory,  the  motor  and  the  electrical  examination.  Evi- 
dences of  lack  of  regeneration,  or  interrupted  regeneration,  and  the  possibility  of 
the  results  to  be  gained  are  guiding  considerations. 

Value  of  Complete  History. — The  history  should  be  an  effort  to  reconstruct 
the  probable  mechanics  of  the  injury,  the  direction  and  nature  of  the  injuring 
force,  so  that  an  attempt  can  be  made  to  determine  the  extent  of  the  trauma  and 
the  point  at  which  the  nerve  has  been  injured.  These  points  are  important  in 
estimating  the  probable  type  of  injury,  whether  it  be  concussion,  interruption, 
injury  by  bony  fragments,  inclusion  by  callus,  etc.  The  nature  of  the  injuring 
force  is  an  important  factor  in  estimating  the  character  of  the  lesion  in  the  nerve 
trunk.  Obviously,  a  blow  of  moderate  force  by  a  blunt  object,  in  a  region  in 
which  the  nerve  is  covered  by  layers  of  muscle,  would  cause  less  damage  to  the 
nerve  than  if  it  were  injured  in  the  more  exposed  situations,  such  as  where 
the  peroneal  nerve  winds  around  the  fibula,  or  the  posterior  interosseous  nerve 
as  it  passes  over  the  radius.  Blows  by  blunt  instruments  are  less  apt  to  cause 
anatomical  interruptions  than  stab  or  incised  wounds,  or  wounds  by  projectiles. 

Local  Examination. — From  the  direction  of  the  injuring  force  one  may 
generally  determine  the  level  of  the  lesion  of  the  nerve  trunk,  but  this  does  not 
always  hold  since  a  bullet  of  high  velocity  may  be  deflected  by  bone  or  even 
tendon,  and  its  course  within  the  tissues  be  turned  from  the  direction  which 
would  be  indicated  by  the  location  of  the  wounds  of  entrance  and  exit.  Thus, 
in  one  patient,  the  wound  of  entrance  was  just  ventral  to  the  semi-tendinosus 
tendon  and  that  of  exit  at  the  junction  of  the  middle  with  the  upper  thirds  of  the 
thigh.  The  patient  had  a  total  paralysis  of  the  peroneal  and  tibial  divisions  of 
the  sciatic  nerve.  It  was  inferred  that  the  injury  to  the  sciatic  was  in  the 
middle  of  the  thigh,  and  exposure  was  made  accordingly.  No  evidence  of 
injury  to  the  nerve  in  this  region  was  found  and  exposure  was  made  lower  down. 

IS7 


IS8         SURGICAL    AND    MKCHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


;.t 


;t, 


The  nerve  was  found  divided  in  the  middle  of  the  pophteal  space,  the  bullet 
apparently  having  been  deflected  in  its  course  within  the  tissues.  (See  Fig.  66.) 
In  another  instance  diagnosed,  however,  before  operation, 
a  hand  grenade  fragment  had  entered  and  made  its  exit  on 
the  mesial  surface  of  the  arm,  in  the  middle  third.  Neither 
the  median  nor  the  ulnar  nerve  was  involved,  as  might  have 
been  expected  from  the  location  of  the  wounds;  but  the 
musculospiral,  which  in  this  position  lies  dorsal  to  the 
humerus,  was  imphcated(  see  Fig.  67)  the  patient  showing  a 
dissociated  paralysis  of  the  musculospiral  nerve.  The  diag- 
nosis was  made  on  the  signs  of  musculospiral  involvement, 
and  discounting  the  evidence  indicated  by  the  location  of 
the  wounds  of  exit  and  entrance.  In  spite  of  such  excep- 
tions which,  in  certain  instances,  may  be  recognized  by  a 
thorough  examination,  the  direction  of  the  injuring  force  is 
usually  an  important  factor  in  localizing  the  site  of  the  nerve 
injury. 

From  the  local  examination,  data  of  immense  importance 
may  be  gained,  which  when  considered  with  the  more  detailed 
neurological  examination  may  be  the  deciding  factor  in  deter- 
mining exploration  in  doubtful  cases.  Other  structures  in 
the  region  of  the  wound  such  as  bones,  muscles,  tendons, 
and  vessels  must  be  investigated.  The  nature  of  a  fracture, 
whether  simple  or  comminuted,  oblique  or  transverse,  and  its 
relation  to  the  nerve  are  important.  Examination  for 
aneurysm,  the  result  of  vessel  injury,  at  the  point  of  nerve  in- 
jury must  not  be  forgotten.  In  injuries  of  the  lower  roots 
of  the  brachial  plexus  above  the  clavicle  the  relation  of  the 
nerves  to  the,  pleura  must  be  borne  in  mind.  The  nerve 
should  always  be  palpated  to  determine  its  density  and  the 
presence  or  absence  of  a  neuroma  and  the  amount  of  scar  tis- 
sue present. 

Sensory  Examination. — The  sensory  findings  must  be 
charted  at  each  examination  so  as  to  form  a  basis  for  future 
comparison.  The  terms  epicritic  and  protopathic  should  be  discarded  and  in 
their  place  each  form  of  sensation  should  be  specifically  designated,  using  the 
term  of  the  stimulus  employed — as  pin  prick  area,  cotton  wool  area,  etc.     The 


Fig.  6  6.— The 
course  of  a  bullet  as 
presumed  from  the 
wound  of  entrance 
and  e.xit  is  shown  by 
a  heavy  line.  The 
actual  course  of  the 
bullet  is  indicated 
by  the  dotted  line. 
Both  divisions  of  the 
sciatic  nerve  were 
severed  in  the  mid- 
dle of  the  popliteal 
space  and  not  in 
the  middle  third  of 
the  thigh  as  was  in- 
f erred  from  the 
wounds  of  entrance 
and  exit. 


INDICATIONS    FOR    OPERATION 


159 


designations  of  discriminative  and  affective,  have  much  to  commend  them. 
However,  for  the  present  at  least,  greater  clearness  may  be  attained  by 
naming  the  stimulus  employed.  For  most  clinical  purposes  the  sensations 
such  as  are  evoked  either  by  cotton  wool  or  pin  point  or  extreme  degrees 
of  temperature  suffice.  If  different  degrees  of  temperature  are  employed, 
the  exact  quantity  of   the    stimulus    may   be  estimated  by  determining  the 


Fig.  67. — The  wounds  of  entrance  and  exit  are  indicated  on  the  medial  surface  of  the  upper 
extremity  (a).  The  point  on  the  dorsal  surface  where  a  small  shell  fragment  was  found  lying  on  the 
musculospiral  nerve  (b).  Such  an  injury  could  not  have  been  anticipated  from  the  position  of  the 
wounds  of  entrance  and  exit  alone. 

temperature  used.  For  this  purpose,  large  metal  tubes  having  a  relatively 
small  point  are  better  than  glass  tubes,  since  glass  does  not  conduct  or 
radiate  temperature  as  does  metal.  If  pin  point  is  used  great  variations  in 
the  amount  of  the  stimulus  employed  occurs  unless  an  instrument  is  used 
which  permits  measurement  of  the  force  of  the  thrust.  For  this  purpose 
several  instruments  have  been  designed,  but  the  algesiometer  of  Casamajor 
and  Strong  has  proven  most  satisfactory  both  because  of  its  simplicity  of 
construction  and  the  facility  with  which  it  may  be  used.     It  consists  of  a  needle 


l6o         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

carried  on  a  spring  steel  band  attached  to  a  ruler  which  is  graded  in  both 
cm.  and  gms.  The  needle  moves  freely  through  an  opening  in  the  ruler. 
By  changing  the  position  on  the  steel  band  at  which  it  is  held  fLxed  varying 
degrees  of  pressure  are  exerted  and  may  be  measured  by  noting  the  mark- 
ings on  the  ruler.  Cobb  (1919)  in  an  excellent  paper,  has  shown  that 
if  comparative  sensory  examination  is  to  be  of  value  it  must  be  made  with 
constant  and  known  stimuli,  alike  both  in  quantity  and  quality. 

In  testing  hght  touch  or  the  cotton  wool  area,  the  part  should  be  stroked 
longitudinally  in  the  extremities,  that  is,  parallel  to  the  limits  of  the  nerve  area 
in  question,  in  order  to  avoid  impinging  upon  adjacent  areas  subserved  by  nerves 
not  involved.  By  this  procedure  Stookey  (1916)  demonstrated  the  sensory  area 
of  the  musculospiral  nerve  on  the  dorsal  part  of  the  distal  phalanx  of  the  thumb, 
theretofore  attributed  to  the  median  nerve.  If  cross  stroking  is  used,  the 
median  area  which  corresponds  to  the  lateral  borders  of  the  nail  is  stimulated 
and  sensation  conveyed  through  the  median  nerve. 

Accurate  sensory  charts  assist  in  estimating  the  presence  and  the  progress 
of  regeneration.  Progressive  shrinking  of  the  area  of  sensory  loss  is  an  excellent 
indicator  of  the  advance  of  nerve  regeneration.  There  is  a  distinct  difference  in 
the  relative  time  of  return  of  sensation  to  cotton  wool,  to  two  point  tests,  to 
moderate  degrees  of  temperature  (discriminative  sensations),  and  to  pain 
extreme  degrees  of  temperature — below  twenty  degrees  and  above  forty  degrees 
— (affective  sensations),  when  stimuli  of  like  quantitative  value  are  employed. 
Finer  appreciation  and  discrimination  return  at  a  later  period  than  the  affective 
forms  of  sensation.  It  is  possible  that  that  form  of  sensation  is  the  first  to  return 
which  is  evoked  by  a  stimulus  of  the  greatest  intensity.  We  know  that  the 
modalities  of  pain  and  temperature  centrally  have  more  interposed  neurons  and 
that  each  interposition  in  the  path  tends  to  lower  the  threshold  and  intensify 
the  preception.  The  affective  forms  are  older  phylogenetically  and  represent 
defense  mechanisms. 

Pain  is  a  more  diffuse  primitive  sensation  than  discriminative  sensation, 
and  according  to  Head,  Rivers,  and  Sherren  (1905-190S)  each  is  served  by  a 
different  set  of  fibers  in  the  peripheral  nerves  acquired  at  different  periods  in  the 
phylogeny  and  functionally  distinct.  Ranson  (191 2)  believes  that  if  this  view 
of  the  afferent  paths  in  the  peripheral  nerves  be  correct  possibly  the  more 
primitive  form  of  sensation  may  be  carried  by  the  more  primitive  tj-pe  of  nerve 
fibers,  namely,  the  nonmedullated;  while  the  more  recently  acquired  forms  are 
served  by  the  more  recently  acquired  fibers — the  medullated. 


INDICATIONS    FOR    OPERATION  lOI 

By  using  the  electrical  methods  of  Lapiccjue  (1907),  Keith  Lucas  (1908), 
Adrian  (1920)  attempted  to  determine  the  presence  of  two  distinct  sets  of 
sensory  fibers.  Lapicque  and  Keith  Lucas  found  that  in  any  given  excitable 
tissue  there  is  a  definite  strength  duration  cur\-e  constant  for  any  given  tissue, 
and  widely  variable  tor  different  tissues.  The  strength  duration  curve  in  non- 
medullated  fibers  was  found  to  be  ten  to  one  hundred  times  as  long  as  in  medul- 
lated  nerve  fibers.  In  testing  the  transmission  of  pain  sensations  inhuman 
sensory  nerves  Adrian  found  the  time  constant  of  the  strength  duration  curve 
to  be  indentical  with  that  found  in  medullated  motor  nerves.  Had  pain  been 
carried  by  the  nonmedullated  fibers  it  would  be  expected  that  the  time  con- 
stant would  have  been  raised.  While  his  experiments  do  not  preclude  the 
existence  of  two  distinct  sets  of  fibers,  no  evidence  of  any  different  time 
constant  was  found.  Adrian  concluded  that  there  was  no  great  structural 
dift'crences  in  the  fibers  carrying  aft'ective  and  discriminative  sensations. 

Motor  Examination. — A  study  of  the  muscular  paralyses  is  of  particular 
importance  for  accurate  level  localization,  since  motor  branches  are  given  oft" 
at  ditt'erent  levels  in  the  course  of  a  ner\-e.  Lidi\'idual  muscular  action  rather 
than  total  movements  must  be  studied.  Letievant  (1872)  showed  that  total 
movements  normally  accomplished  by  definite  muscle  groups  in  certain  paraly- 
ses may  be  performed  by  some  of  the  group  or  by  muscles  belonging  to  other 
physiological  groups  of  different  nerve  supply.  For  example,  the  flexion  action 
of  the  biceps,  supinator  longus,  and  brachialis  may  be  performed  by  any  one  of 
this  group;  whereas  normally  they  all  take  part  in  flexion  of  the  forearm  and 
act  as  a  synergic  unit  in  the  total  movement  of  flexion,  yet  individually  each 
may  accomplish  the  movement  without  the  assistance  of  the  others.  In  injury 
of  the  musculocutaneous  nerve  with  paralysis  of  the  biceps  and  brachialis,  flexion 
of  the  forearm  may  be  accomplished  with  great  force  by  the  supinator  longus — 
supplied  through  the  musculospiral  nerve.  In  testing  muscular  action,  it  is 
desirable  to  palpate  both  the  muscle  belly  and  the  muscle  tendon,  to  determine 
more  accurately  the  role  any  single  muscle  is  playing  in  any  given  movement. 

Electrical  Examination. — Faradic  and  galvanic  examination  of  the 
nerve  and  muscle  is  indispensable.  In  nerve  injuries  the  faradic  response  is 
lost  early  and  is  late  to  return,  reappearing  generally  a  considerable  time  after 
the  return  of  voluntary  contraction.  Faradic  inexcitability  of  the  nerve 
and  muscles  is  found  in  any  condition  in  which  ner\-e  conducti\'ity  is  interrupted. 
The  thick  wire  coil  is  usually  used  and  the  examinations  made  on  the  nerve 
both  above  anfl  below  the  level  of  injury  after  having  first  obtained  the  far- 


l62         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

adic  threshold  for  the  individual  by  stimulation  of  the  corresponding  nerve 
on  the  sound  side.  The  muscles  supplied  by  the  nerve  in  question  are  also 
tested  using  the  threshold  that  has  been  obtained  by  examination  of  the 
corresponding  muscles  on  the  opposite  side,  employing  a  sufficient  stimulus 
to  obtain  a  minimal  contraction.  A  simple  hypo-excitabihty  may  be  found 
and  if  strong  currents  are  used  the  stimulus  is  diffused  and  adjacent  muscles 
are  stimulated  thus  confusing  the  examination. 

The  nerve  and  muscle  are  also  tested  with  the  galvanic  current.  In 
order  that  comparisons  with  subsequent  examinations  may  be  made  the  form 
and  nature  of  the  muscular  contractions  as  well  as  the  strength  of  current 
required  to  obtain  a  minimal  response  should  be  carefully  noted.  The  normal 
muscular  contraction  to  the  galvanic  current  is  a  sharp,  quick  twitch.  The 
contraction  is  greater  on  closure  from  the  negative  pole  than  from  the  positive. 
The  minimal  threshold  for  each  pole  should  be  determined  on  the  normal  side 
and  comparisons  made  with  the  injured.  Variations  in  the  strength  of  current 
required  are  found  in  different  indiiaduals  and  at  different  points  on  corre- 
sponding muscles.  Normally  two  niilliamperes  are  required  when  the  muscle 
is  stimulated  at  the  motor  point,  but  if  the  exact  motor  point  is  not  found  the 
threshold  will  be  materially  raised  even  up  to  five,  six  or  eight  niilliamperes. 
In  motor  paralysis  the  minimal  threshold  at  the  motor  point  may  be  raised 
ten  to  fifteen  times  and  generally  the  maximum  contraction  is  not  obtained 
from  the  motor  point,  but  over  the  junction  of  the  muscle  fibers  with  the 
tendon.  This  shifting  of  the  point  of  greatest  excitability  is  commonly  known 
as  the  "longitudinal  reaction."  This  reaction  is  due  to  the  fact  that  in  para- 
lyzed muscles  the  motor  point  is  in  reality  no  longer  present,  since  the  motor 
twig  to  the  muscle  is  inexcitable,  however,  the  muscle  fibers  have  retained  their 
excitability.  At  the  junction  of  the  muscle  and  tendon  a  maximum  number 
of  muscle  fibers  are  brought  together  and  a  stimulus  applied  at  this  point 
affects  a  greater  number  of  fibers  than  at  any  other  point — consequently  the 
response  is  greater. 

In  normal  muscle  the  response  to  galvanic  current  is  greater  on  closure 
from  the  negative  pole  than  from  the  positive  pole.  In  nerve  injuries  the 
reaction  may  be  altered  and  an  equal  response  obtained  on  closure  from  each. 
This  is  spoken  as  of  "polar  equality."  When,  on  the  other  hand,  the  response 
obtained  on  closure  from  the  positive  pole  is  greater  than  from  the  negative  a 
"reversal  of  polarity"  is  said  to  exist  and  this  is  usually  indicative  of  complete 
anatomical  interruption.     The  degree  of  muscular  degeneration  is  indicated  by 


INDICATIONS    FOR    OPERATION  I  63 

the  nature  of  the  muscular  response,  varying  from  a  relatively  slow  contraction 
in  the  earliest  stages  to  a  slower  wave-like  contraction  and  on  to  galvanic 
inexcitability  in  the  latest  stages  of  muscular  degeneration  where  muscle  tissue 
is  reduced  to  a  minimum  if  not   altogether   replaced  by   connective   tissue. 

The  reaction  of  complete  degeneration  consists  in  faradic  and  galvanic 
inexcitability  of  the  nerve;  faradic  inexcitability  of  the  muscle  and  an  alteral- 
tion  in  the  muscular  response  to  galvanism  consisting  of  a  slow,  wave-like 
contraction  with  longitudinal  reaction.  Polar  equality  or  polar  inversion  of 
the  formula  may  be  present.  In  the  more  severe  and  long-standing  paralysis 
galvanical  inexcitability  is  found.  The  various  changes  in  the  electric  response 
progress  gradually,  only  in  the  final  stages  reaching  galvanic  inexcitability. 
The  entire  gamut  of  changes  is  not  seen  in  every  case  for  their  progress  may  be 
interrupted  at  any  period  by  beginning  regeneration. 

Results  of  electrical  examination  indicate  the  presence  of  an  organic 
peripheral  nerve  injury,  thus  differentiating  it  from  hysteria,  and  furthermore 
indicate  whether  interruption  of  conductivity  is  complete  or  incomplete  and  the 
relative  degree  of  degeneration  in  the  muscles.  Differentiation  cannot  thus  be 
made  between  complete  anatomical  interruption  and  complete  physiological 
interruption. 

Thus  by  combining  the  information  gained  from  the  liistory  of  the  trauma 
with  that  from  the  sensory,  motor  and  electrical  examinations,  the  presence  or 
absence  of  nerve  conductivity  may  be  determined.  But  whether  or  not  an 
interrupted  nerve  will  go  on  to  spontaneous  regeneration  can  be  determined  only 
by  making  repeated  examinations  and  by  waiting  sufficiently  long  for  signs  of 
regeneration  to  take  place,  or  by  exploratory  nerve  operation  though  the  latter 
may  not  be  conclusive.  These  signs  of  regeneration  may  appear  from  two 
to  thirty  months  after  the  nerve  injury.  Frazier  and  Silbert  (1920)  are  of  the 
opinion  that  in  the  majority  of  instances  nerve  compression,  neuroma  in  con- 
tinuity and  complete  anatomical  interruption  may  be  determined  by  complete 
sensory  motor  and  electric  examinations.  "In  compression  there  was  complete 
motor  paralysis  in  45%,  complete  sensory  loss  in  15%,  and  no  case  with  com- 
plete reactions  of  degeneration.  In  complete  anatomical  interruption  there  was 
complete  motor  loss  in  100%,  complete  sensory  loss  in  86%,  and  complete 
reactions  of  degeneration  in  85%.  (The  absence  of  complete  sensory  loss  or 
reaction  of  degeneration  in  the  minority  may  be  attributable  to  the  fact  that  in 
the  scar  tissue  intervening  between  the  divided  segments  a  few  indistinguishable 
fibers  may  have  been  present.)     The  neuroma  in  continuity  presented  a  picture, 


164 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


as  one  might  expect,  intermediate  between  compression  and  interruption. 
Thus  there  was  complete  motor  loss  in  only  74%,  incomplete  in  26'^'^,;  complete 
sensory  loss  in  only  3,^%,  incomplete  in  67%,  complete  reaction  of  degeneration 
in  16.5%,  incomplete  in  83.5%."     (See  Chart  III.) 


Chart  III. — Showing  percentage  of  incomplete  and  complete  motor,  sensory,  and  electrical  syn- 
dromes in  compression,  C,  neurome  in  continuity,  N,  and  anatomical  interruption,  I.  (C.  H. 
Frazier  and  S.  Silbert,  in  Surg.,  Gyn.  and  Obst.) 

Signs  of  Regeneration.^Xhe  earhest  evidence  of  regeneration  is  found  in 
an  improvement  of  the  vasomotor  status  of  the  part.  This  change  may  be 
extremely  early,  often  earlier  than  can  be  accounted  for  by  the  growth  of  re- 
generating nerve  fibers.  There  is  a  gradual  increase  in  the  tone  of  the  paralyzed 
muscles,  with  a  coincident  decrease  in  the  degree  of  the  deformity,  before  any 
signs  of  return  of  voluntary  contraction  appear.  Beginning  regeneration  is 
manifested  in  the  change  in  the  response  of  paralyzed  muscle  to  electrical 
stimulation.  If  polar  inversion  has  been  present,  with  beginning  regeneration, 
this  is  changed  to  polar  equality  and  the  slow  wave-like  contraction  gradually 
becomes  more  rapid  with  a  return  from  the  longitudinal  reaction  to  the  motor 
point  reaction.  Faradic  response  usually  does  not  return  until  after  return  of 
voluntary  contraction,  though  this  is  not  invariably  the  rule.  At  first  attempts 
at  voluntary  movements  are  manifested  only  by  a  slight  increase  in  the  tone  of 
the  muscles,  frequently  associated  with  contraction  of  the  entire  musculature 
of  the  extremity,  especially  the  antagonist  group,  and  spreading  even  to  the 


INDICATIONS    FOR    OPERATION  165 

opposite  limb,  when  great  efforts  are  made  to  transmit  the  impulse  to  the  rein- 
nervated  muscles.  The  muscles  regain  their  innervation  in  the  order  from 
above  downward  of  the  origin  of  their  branches  from  the  nerve  trunk,  i.e., 
those  branches  proximal  to  the  injury  are  reinnervated  earlier  than  the  more 
distal.  The  intervals  in  successive  innervation  of  muscle  groups  may  be 
comparatively  long  if  the  muscle  branches  are  given  off  far  apart,  due  to  the 
additional  time  required  for  the  neuraxes  to  travel  the  added  distance.  Duroux 
and  Couvreur  (1917)  and  Tinel  (1919)  found  that  the  neuraxes  grow  at  about 
the  rate  of  i  to  2  mm.  per  day. 

Following  closely  the  improvement  in  vasomotor  status  and  tone,  the 
muscles  become  sensitive  to  deep  pressure  and  a  beginning  return  of  faradic 
sensation  in  the  skin  and  muscles  is  found.  A  gradual  shrinkage  of  the  cut- 
aneous anesthetic  areas  occur,  those  for  pain  and  extreme  degrees  of  tem- 
perature being  the  first  to  show  contraction  of  their  borders,  while  those  for 
cotton  wool  and  moderate  degree  show  evidence  of  return  only  late. 

The  early  return  of  tone,  and  the  decrease  in  the  postural  deformity  of 
the  extremity  with  the  absence  of  voluntary  movements  after  the  normal 
associated  movements  returned  in  certain  cases,  led  Ramsay  Hunt  (1918)  to 
extend  his  fascinating  conception  of  the  neokinetic  and  paleokinetic  motor 
systems  to  peripheral  nerves  and  predicate  in  them  the  existence  of  two  sets 
of  motor  fibers  such  as  Head,  Rivers  and  Sherren  had  similarly  done  for  sen- 
sory fibers.  The  strongest  evidence  in  support  of  Hunt's  view  are  certain 
related  facts,  anatomical  rather  than  clinical.  Hunt  calls  attention  to  the  well- 
known  functional  differences  in  the  sarcoplasm  and  the  sarcostyles.  The 
sarcoplasm  is  concerned  with  the  slow  tonic  sustained  phases  of  muscular 
contraction,  and  postural  function,  while  the  sarcostyles  are  involved  in  rapid 
quick  muscular  contraction.  The  functional  differences  of  sarcoplasm  and 
sarcostyles  advanced  by  Bottazzi  (1897)  and  elaborated  by  Roaf  (1912)  has 
been  generally  accepted.  Pekelharing  and  van  Hoogenhuyze  (1910)  have  found 
that  there  are  two  distinct  chemical  catabolic  changes  in  muscle,  one  the 
result  of  ordinary  contraction  and  the  other  characteristic  of  tonic  activity.  It 
has  been  shown  that  light  muscle  has  more  sarcostyles  than  dark  muscle  and 
that  the  rapidity  of  contraction  is  greater  in  light  than  in  dark  muscle.  Boeke 
(1909)  found  that  both  meduUated  and  nonmeduUated  nerve  fibers  form  end 
plates  in  striated  muscle.  In  later  experiments  Boeke  and  De  Barenne  (1919) 
corroborated  this  view  by  further  experimentation.  These  investigators  cut  the 
ventral  and  dorsal  roots  of  the  sixth,  seventh  and  eighth  thoracic  nerves  with 


1 66         SURGICAL   AND   MECHANICAL   TREATMENT    OF   PERIPHERAL   NERVES 

excision  of  the  corresponding  spinal  ganglia,  and  studied  the  nerve  endings  in 
the  intercostal  muscle  of  the  seventh  space.  They  found  that  all  medullated 
nerve  fibers  and  end  plates  had  disappeared,  while  there  still  remained  bundles 
of  tine  nonmedullated  nerve  fibers  connected  with  muscle  fibers  by  means  of 
delicate  end  organs.  These  were  hypolemmal  and,  therefore,  presumably 
motor  in  function.  Similar  experiments  with  similar  results  were  reported  by 
Agduhr  (1919)  after  cutting  the  last  four  cervical  and  first  two  thoracic  nerves 
distal  to  the  spinal  ganglia  and  proximal  to  the  white  rami  communicantes. 
Degeneration  of  all  medullated  nerve  fibers  was  found  while  unaltered  non- 
medullated fibers  with  their  end  organs  were  present.  Approaching  the  subject 
from  the  opposite  angle,  Agduhr  removed  the  stellate  ganglion  without  injuring 
the  spinal  nerves  and  found  in  the  muscle  studied  degenerate  nonmedul- 
lated fibers  and  unaltered  medullated  fibers.  Ranson  (191 2)  showed  that  there 
are  many  more  nonmedullated  nerve  fibers  in  the  peripheral  nerves  than 
heretofore  had  been  believed.  The  nonmedullated  fiber,  the  sarcoplasm,  and 
the  slow  sustained  contraction  are  more  primitive  than  the  medullated  fiber, 
the  sarcostyles  and  the  quick  rapid  contraction ;  phylogenetically  more  recent 
acquisitions.  Hunt  beheves  that  the  paleokinetic  system  is  less  vulnerable  and 
regenerates  more  rapidly  than  the  neokinetic  system,  which  may  account  for  the 
earlier  return  of  the  simpler  and  more  primitive  functions  such  as  pain  and 
thermal  sensations  and  muscular  tone,  the  slow  tonic  contraction  and  postural 
functions.  Whatever  view  of  Hunt's  theory  be  taken,  nevertheless,  he  has 
advanced  a  plausible  conception  on  a  teleological  basis  to  explain  the  sequence 
of  returning  function  following  peripheral  nerve  injury. 

Tinel's  Sign;  "le  signe  du  fourmillenient." — A  sensation  of  electricity 
referred  to  the  peripheral  cutaneous  distribution  of  the  nerve,  produced  by 
pressure  on  the  nerve  trunk,  was  proposed  by  Tinel  as  a  means  to  determine 
not  only  the  existence  of  regeneration  but  also  its  progress.  This  sensation  of 
formication  is  rarely  perceived  at  the  point  pressed,  but  is  much  more  actively 
resented  in  the  peripheral  cutaneous  distribution  of  the  nerve  in  question, 
thereby  distinguishing  it  from  that  of  neuritis.  This  sign  was  said  to  be 
found  only  when  newly  formed  neuraxes  are  present  in  the  nerve  trunk,  and 
is  progressive  along  the  course  of  a  nerve  undergoing  regeneration,  advanc- 
ing pari  passu  with  the  downgrowth  of  neuraxes. 

The  presence  of  this  sign  in  a  given  case,  if  interpreted  as  evidence  of 
regeneration,  would  be  a  contraindication  to  operation.  However,  it  has 
been  shown  that  Tinel's  sign  may  be  present  when  there  is  practically'no  ana- 


INDICATIONS    FOR    OPERATION 


167 


tomical  continuity,  or  only  a  few  stray  neuraxes  within  the  distal  segment; 
and  consequently  it  alone  cannot  be  taken  to  indicate  functional  regeneration. 


Fig.  6S. — The  value  of  Tinel's  sign.  In  this  patient  Tinel's  sign  was  obtained  from  both 
division  of  the  sciatic  below  the  knee.  Obviously  spontaneous  functional  regeneration  could  not 
have  taken  place  for  the  sciatic  nerve  was  completely  severed  and  a  dense  wall  of  scar  tissue  intervened 
between  the  ends.     (Stookey,  Neurol.  Bull..  igiQ.j 

(See  Figs.  68,  69  and  70.)  Experience  has  taught  that:  (i)  Tinel's  sign  may  be 
elicited  when  regenerating  neuraxes  are  present  within  the  nerve  trunk,  irre- 
spective of  their  number;  (2)  such  neuraxes  may  be  found  when  functional 
regeneration  is  impossible,  due  either  to  excessive  scar  or  to  dispersion  of  the 
neuraxes,  with  few  penetrating  the  distal  stump;  (3)  Tinel's  sign,  although 
present  and  progressive  in  its  course  downard  along  the  nerve  trunk,  cannot 


[68 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


alone  be  considered  evidence  of  satisfactory  regeneration;  (4)  Tinel's  sign  is 
of  greatest  value  when  the  anatomical  field  is  known,  that  is,  following  opera- 
tion, and  when  considered  with  other  c\idences  of  regeneration.     Here  its 


Fig.  69. — The  value  of  Tinel's  sign.     The  same  as  Fig.  68  with  the  dissection  carried  one  step 
farther.     Xo  gross  evidence  of  doungrowth  of  neuraxes.     (Stookey,  Xeurol.  Bull,,  1919.) 


main  limitations  are  removed,  since  the  nerve  ends  are  known  to  be  in  ana- 
tomical apposition  and  in  a  position  to  favor  downgrowth. 

Time  of  Regeneration  Following  Suture. — Evidences  of  regeneration  are 
rarely  found  earlier  than  the  third  or  fourth  month  and  may  appear  at  any 
time  thereafter  even  up  to  thirty  months.  The  time  required  is  influenced 
by  a  great  variety  of  factors  which  make  it  impossible  to  set  a  definite  standard 


IXDICATIONS    FOR    OPERATION 


169 


time  for  regeneration  applicable  to  all  nerves.  The  period  varies  with  each 
nerve  and  the  level  of  the  injury  on  the  nerve.  It  also  varies  with  the  level 
of  the  injury  of  the  nerve  trunk  and  its  relation  to  the  origin  of  nerve  branches. 
When  a  nerve  trunk  is  injured  only  a  short  distance  above  the  point  at  which  a 


Fig.  70. — The  value  of  Tinel's  sign.  In  this  patient  i  uifl  s  sign  was  present  in  the  distal  part 
of  the  median  nerve  and  progressed  gradually  downward  as  far  as  the  palm.  Only  a  slender  strand 
of  tissue  continuity  existed.  Functional  regeneration  could  not  have  taken  place  spontaneously. 
(Stookey,  Neur.  Bull.) 


group  of  branches  is  given  off,  innervation  of  the  muscles  supplied  by  these 
branches  may  take  place  relatively  early,  whereas  if  a  considerable  distance 
intervenes  between  the  point  of  injury  and  the  origin  of  the  motor  branches,  a 
longer   period    would    be   required    before    evidences    of    regeneration  would 


I/O 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


appear.  Additional  factors  influencing  the  rate  of  regeneration  are  the  time 
interval  between  injury  and  suture,  presence  or  absence  of  infection,  the  condi- 
tion of  the  nerves  found  at  operation,  the  type  of  operation,  the  nature  of  the 
nerve  bed  and  the  preoperative  and  postoperative  treatment.  Injuries  more 
proximally  placed  regenerate  better  than  those  more  distal. 

Table  IV  gives  a  rough  idea  of  the  approximate  time  at  which  evidences  of 
regeneration  may  be  expected  in  the  nerves  most  commonly  injured  and  at 
levels  most  frequently  seen.  The  time  limits  are  those  which  obtain  under 
ordinary  good  and  ordinary  poor  conditions  as  determined  by  the  variants 
mentioned,  but  variations  from  these  time  limits  are  seen,  for  example  one 
musculospiral  nerve  showed  advance  signs  of  regeneration  in  three  months  and 
one  ulnar  not  until  thirty  months. 


Table  IV. — F.iCTORS  Governixg  Prognosis  .and  Time  of  REGENER.-iiiON  ix  Various  Nerves 

.\.  Variants  controlling  regeneration. 

I.  Nerve  injured. 
II.  Level  of  injury. 

III.  Mechanics  of  suture. 

IV.  Condition  of  nerve  ends. 

V.  Condition  of  wound  and  nerve  bed. 
VI.  Interval  between  injury  and  suture. 
B.  Approximate  time  for  expectant  evidences  of  regeneration. 


Nerve  and  level 

Under  good  conditions, 
months 

Under  poor  conditions, 
months 

Musculocutaneous: 

Axilla                            

S-6 

7-8 
6-7 

5-7 

IO-I2 
15-16 

4-S 

8-9 

12-14 

10-12 

12-14 

8-9 
10-12 

11-12 

8-10 

ilusculospiral: 

Middle  third  arm                               

14 

Lower  third  arm                                     ... 

12 

Ulnar: 

Wrist                      

10 

16 

Axilla                   

22 

Median: 

Wrist  

10 

Elbow                         

IS 

Axilla                      

18 

Sciatic : 

Middle  third  thieh                

18 

Unoer  third  thi^h                  

22 

Peroneal : 

14 

16 

Tibial: 

Popliteal  space 

17 

INDICATIONS    FOR    OPERATION  171 

Interrupted  Regeneration  and  Reoperation.—  Interrujition  of  regeneration 
may  take  place  in  any  stage.  It  is  indicated  by  cessation  in  the  progress  of 
the  signs  above  described  as  indicating  regeneration.  Regeneration  having 
aheady  begun  may  be  temporarily  retarded  at  certain  periods  due  to  scar  tissue 
or  other  factors  inhibiting  the  passage  of  the  neuraxes.  The  surgeon  must  be 
very  cautious  in  determining  upon  reoperation  in  an  apparent  interrupted 
regeneration,  for  in  many  cases  the  interruption  may  be  only  temporary  and 
regeneration  ultimately  take  place  without  interference.  But  if  no  signs  of 
regeneration  appear  re-exploration  of  the  wound  is  indicated.  No  definite 
time  limit  can  be  set  applicable  to  all  nerves  and  to  all  sutures.  Each  must  be 
judged  individually  and  with  knowledge  of  the  anatomical  field,  the  nature 
of  the  suture,  the  condition  of  the  nerve  ends  and  the  cross  areas  obtained  at 
the  time  of  suture  as  well  as  the  relative  position  at  which  branches  are  given  off. 
It  has  been  the  author's  custom  to  make  a  definite  prognosis  as  to  regeneration 
and  time  for  beginning  regeneration  immediately  after  each  operation  and 
to  indicate  any  probable  causes  of  failure  which  may  be  anticipated,  either 
because  of  the  condition  of  the  nerve  ends  or  the  mechanics  of  the  suture.  Simi- 
larly, if  nerve  branches  have  been  destroyed  these  are  indicated  and  a  note  made 
that  regeneration  of  their  muscles  is  not  to  be  expected.  Re-exploration  for 
failure  to  regenerate  may  be  done  earlier  when  no  signs  of  regeneration  have 
appeared  than  when  regeneration  begun  is  interrupted. 

A  fusiform  and  relatively  soft  bulb  is  usually  found  at  the  line  of  suture  and 
should  not  be  taken  to  indicate  blocked  regeneration.  But  if  the  bulb  is  hard 
and  the  enlargement  appears  only  on  the  central  end,  without  any  increase  in 
size  distal  to  the  suture,  it  indicates  some  obstruction  to  regeneration.  In  nerve 
transplantation,  especially  when  a  long  defect  has  been  bridged,  re-exploration 
of  the  distal  suture  with  excision  of  the  distal  union  and  resuture,  end  to  end, 
may  be  done,  since  scar  tissue  at  the  distal  union  may  become  too  dense  before 
the  neuraxes  have  gained  the  distal  stump  to  permit  their  passage. 

Criteria  for  Estimating  Results.- — In  order  that  the  cases  of  spontaneous 
regeneration  and  the  results  of  nerve  suture  may  be  compared  without  confusion 
a  standard  terminology  should  be  used.  The  terms  suggested  by  Gosset 
(191 7)  have  already  been  used  extensively  and  warrant  adoption.  The  cases 
are  classified  as  unimproved,  improved,  markedly  improved  and  recovered.  Under 
"improvement"  are  classified  those  with  definite  evidence  of  regeneration  as 
indicated  by  return  of  tone,  some  voluntary  movement,  faradic  response, 
disappearance  of  trophic  changes  or  by  some  return  of  sensation.     As  "mark- 


172  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

edly  improved,"  when  voluntary  movements  in  previously  paralyzed  muscles 
have  almost  completely  returned,  but  to  an  extent  less  than  can  be  considered 
as  absolute  recovery — irrespective  of  the  electrical  response  or  the  sensation 
return.  As  "recovered,"  when  voluntary  control  of  all  muscles  has  returned, 
although  some  alteration  in  the  electrical  reactions  may  still  exist  or  sensation 
be  not  completely  regained.  In  estimating  motor  return  the  action  of  each 
separate  muscle  must  be  recorded  and  not  group  or  total  movements. 

There  is  probably  no  problem  more  delicate  or  requiring  greater  nicety  of 
judgment  than  the  indications  for  operation  in  nerve    injuries.     Indeed  it  is 

Percent  almost  impossible  to  give  definite 

40       50       60    70        So     00     100 

general  rules  since  a  great  deal 
depends  on  the  nerve  injured,  the 
level  of  the  lesion  and  the  nature 
of  the  local  injury.  In  a  nerve 
supplying  small  muscles  serving 
fine  movements,  delay  in  recovery 
is  more  harmful  than  in  a  nerve 
to  larger  muscles  of  coarser  move- 
ments.     Again,    the   nearer    the 

injury     to    the    spinal    cord    the 

Ch.^rt  IV. — Table    to  show   the    relative  frequency  .         .1  ,■ 

,  .  J    r  greater   the   power   oi  retjenera- 

01    operations    on    each    nerve    computed,   trom   1200    ^^  ^  ■- 

nerve     operations.      These     inckide     operations    from    tion.       Greater    vulnerability     of 

various  chnics.  .,  i-   ^   1  -ci  •        1 

the  more  distal  fibers  is  also  seen 

in  the  neuropathies,  in  which  conditions  the  more  distal  fibers  are  earlier  and 
more  severely  involved.  When  the  local  injury  is  so  extensive  that  the  sur- 
rounding tissues  are  nothing  but  a  mass  of  scar  and  callus  delay  in  operation 
hardly  seems  justified.  With  such  a  diversity  of  controlling  factors  it  is  obvi- 
ously impossible  to  set  down  any  rule  applicable  to  all  nerve  injuries.  Each 
must  be  individually  considered. 

Time  of  Operation. — In  war  wounds  and  in  certain  civil  wounds  immediate 
suture  is  rarely  possible  due  to  existing  infection.  Immediate  primary  suture 
at  the  time  of  the  injury  is  the  ideal  whenever  possible.  Results  from  primary 
suture  are  better  than  from  secondary — not  only  in  time  recjuired  for  regenera- 
tion but  in  completeness  of  recovery.  Other  things  being  equal,  a  long  interval 
between  the  injury  and  the  repair  diminishes  the  chance  of  complete  recovery, 
not  only  because  of  the  changes  occurring  within  the  nerve  itself  but  also 
because  of  changes  in  the  structures  supplied  by  the  nerve,  particularly  muscles. 


INDICATIONS    FOR    OPERATION 


173 


It  is  a  fundamental  principle  of  nerve  surgery  that  all  operations  must  be 
done  in  a  sterile  field,  consequently  in  many  civil  and  war  wounds  suflicicnt 
time  must  elapse  to  insure  a  noninfected  field.  The  possibility  of  recrudescence 
of  infection  in  an  apparently  healed  wound  must  always  be  considered,  more 
especially  where  there  has  been  extreme  comminution  of  a  fracture  or  when 
scattered  metal  fragments  remain  in  the  wound.  Small  foreign  bodies,  such 
as  bone  or  metal  fragments,  may  be  found  in  a  small  amount  of  mucopurulent 
fluid  walled  off  by  scar  tissue  and  this  when  spread  may  light  up  infection. 
The  presence  of  such  fragments 
may  be  determined  by  a;- ray  and, 
when  found,  indicate  the  need 
of  a  longer  delay. 

When  secondary  operation 
only  is  possible,  at  what  period 
should  it  be  performed?  The 
first  consideration,  as  has  been 
said,  is  the  possibility  of  a  sterile 
held;  the  second  is  the  nature 
of  the  trauma  and  the  absence 
of  progressive  regeneration. 
Statistics  in  this  country  and 
abroad  indicate  that  between  40 

to  60%  of  nerve  injuries  may  ^recover  without  operation 
(1914),  reporting  cases  from  the  Balkan  War,  estimated  that  40%  recov- 
ered, while  Tinel,  m  this  war,  places  the  percentage  higher— 60%.  Frazier 
(1920J  found  that  among  live  hundred  cases  63%  recovered  without 
operation.  Yet  some  statistics  show  that  in  about  60%  of  all  nerve  oper- 
ations complete  interruption  is  found  with  little  or  no  chance  of  spontaneous 
recovery. 

Statistics  showing  recovery  without  operation  do  not  take  into  account 
the  time  necessary  for  spontaneous  recovery.  It  is  suggested  that  possibly 
had  these  spontaneous  regenerations  been  explored  early,  nerve  Hberation  would 
have  been  done  and  regeneration  hastened.  It  is  a  noteworthy  fact  that 
following  nerve  liberation  many  cases  show  surprisingly  rapid  return  of  func- 
tion, some  within  a  few  days  and  others  a  few  weeks.  Consequently  it  is  fair 
to  assume  in  a  considerable  portion  of  the  cases  regenerating  spontaneously 
without  operation,  that  the  time  of  convalescence  might  be  materially  shortened 


Musculospiral 
Ulnar 

Sciatic 

^VB^ 

Median 

^^^^^^^ 

Pcrnoneal 

^^^^M^ 

B.a.iiial     Plexus 

^^^r 

Tibial 

1 

Facial 

r 

C'iicuniflcx 

r 

Anterior     Crural 

1 

Miscellaneous 

■ 

Chart  V.— Table  to  show  relative  frequency  of    vari- 
ous nerve  injuries  compiled  from  12 10  war  injuries. 

Gerulanos 


174 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


by  conservative  nerve  exploration  and  nerve  liberation — in  most  instances  a 
comparatively  slight  operation. 

Neurological  opinion  is  agreed  that  the  signs  which  we  ha\-e  at  our  disposal 
do  not  permit  the  distinction  being  made  between  complete  anatomical  and 
complete  physiological  interruption.  Immediately  after  the  nerve  injury,  and 
for  the  next  two  or  three  weeks,  the  affected  muscles  preserve  their  mechanical 
and  electrical  irritability.  Gradually  they  lose  their  electrical  excitability 
to  the  faradic  current  while  preserving  their  galvanic  responses,  later 
showing  the  so-called  reaction  of  degeneration.  During  the  first  few  weeks 
after  nerve  injury  the  usual  direct  mechanical  irritability  of  the  muscle  is 

preserved,  or  even  increased 
after  the  faradic  response  is 
lost.  During  the  early  stages, 
the  muscle  responds  to  direct 
percussion  by  sharp  cjuick  con- 
traction; but  in  the  later  stages, 
when  the  reaction  of  degenera- 
tion is  present,  the  contraction 
wave  is  slow  and  vermicular 
in  character.  When  this  con- 
traction   wave    is  present,   the 


achial     Plesiil 

Ulnar 

^^^^^ 

Facial 

^^^^r^ 

Median 

^^^^r 

Musculospiral 

^^^1 

Personeii 

^H^^ 

Miscellaneous 

^■Hl 

Chart  VI. — Table  to  show  relative  frequency  of 
various  peripheral  nerve  lesions  in  civilian  life.  Com- 
piled   from  200  cases. 


electric  reaction  of  degeneration  may  be  presumed  also  to  be  present,  and 
when  the  response  to  direct  mechanical  stimulation  is  lost  the  muscle  is  in  the 
last  stages  of  degeneration. 

With  the  exception  of  partial  and  incomplete  nerve  injuries,  it  is  unfortu- 
nately impossible,  as  has  been  said,  to  determine  whether  a  nerve  will  recover 
without  operation  except  by  waiting  a  sufficient  length  of  time  to  allow  for 
evidences  of  nerve  regeneration  to  manifest  themselves.  It  has  been  customary 
to  wait  from  three  to  four  months  for  regeneration  and  then,  if  sufficient  evi- 
dences of  regeneration  are  not  present,  to  operate.  However,  a  large  number  of 
cases  have  been  reported  which  have  shown  the  first  evidence  ot  regeneration 
eight  and  nine  months  after  the  injury  and  have  gone  on  subsequently  to  recov- 
ery. It  is  well  known  that  many  nerves  regenerate  after  twenty  or  even 
thirty  months.  Hence  to  select  arbitrarily  three  or  four  months  as  the  period 
to  await  regeneration,  as  has  been  the  custom,  does  not  seem  to  be  based 
on  rational  grounds.  In  effect,  operation  after  four  months  of  waiting  is  often 
nothing  more   than   deferred  exploration.     Price  (1919),  from  a  wide  experi- 


INDICATIONS    FOR    OPERATION  175 

ence  in  the  American  Ambulance,  felt  that  the  anatomical  field  frequently  shows 
a  hopeless  situation  and  that  by  delay  nothing  results  except  a  loss  of  time  for  the 
patient.     Such  certainly  has  been  my  own  experience. 

However,  if  the  conditions  be  known — that  is,  the  status  of  the  surrounding 
tissues  and  the  relation  of  the  nerves  to  them,  and  whether  there  is  anatomical 
interruption  or  only  physiological  block,  such  as  might  be  gained  by  early 
exploration — regeneration  may  then  be  awaited  with  some  degree  of  assurance, 
since  the  clinical  signs  of  regeneration  may  be  better  evaluated. 

Early  nerve  exploration  seems  to  me  to  offer  a  possible  means  of  diminishing 
delay  in  recovery  and  at  the  same  time  give  an  opportunity  to  facilitate  regen- 
eration. To  explore  a  nerve  involves  little  danger  to  the  patient  and  may 
offer  the  tremendous  advantage  of  hastening  recovery.  Most  nerves  are  more 
or  less  superficial  and  their  exposure  is  comparatively  simple. 

In  any  nerve  injury  with  a  history  of  trauma  sufficient  to  warrant  the 
belief  that  the  nerve  may  have  been  severed  or  embedded  in  scar  or  callus,  etc., 
nerve  exploration  should  be  done  as  early  as  the  condition  of  the  wound  will 
admit.  Exploration  should  be  done  by  one  familiar  with  the  appearance  of 
injured  nerves  as  found  at  operation  and  with  an  intimate  knowledge  of  the 
histology  of  nerve  repair.  The  need  of  conservatism  during  nerve  exploration 
cannot  be  too  insistently  urged.  The  rule  should  be  radical  nerve  exploration 
but  conservative  nerve  operation. 

In  a  certain  number  of  cases  even  by  early  exploration  the  surgeon  will  be 
unable  to  decide  with  certainty  whether  to  excise  and  suture  or  to  leave  the 
nerve  alone.  On  the  other  hand,  nerves  anatomically  interrupted  may  be 
sutured  at  once  with  the  saving  of  much  time  for  the  patient  and  with  the 
assurance  of  a  more  complete  return  of  function.  Of  two  hundred  and  fifty- 
three  cases  operated,  one  hundred  and  sixty-one  showed  complete  interruption, 
and  in  these  the  anatomical  field  always  appeared  worse  than  was  anticipated 
from  the  neurological  findings  or  the  appearance  of  the  local  injury.  Thus,  in 
more  than  63%  of  those  operated  conditions  requiring  nerve  suture  are  to  be 
found. 

The  limitations  of  nerve  exploration  must  be  constantly  in  mind,  for  it  is 
only  with  a  realization  of  this  that  nerve  exploration  may  be  safely  advocated. 
We  may  divide  nerve  injuries  into  three  groups,  in  view  of  the  anatomical  find- 
ings at  operation:  those  with  anatomical  interruption  (63%);  those  having 
apparently  only  slight  injury  and  yet  with  physiological  interruption;  and, 
between  these  two  extremes,  a  doubtful  group  which  merges  on  one  side  into 


176         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

the  anatomical  interruptions  and,  on  the  other,  the  sHght  injuries.  In  this 
middle  group,  nerve  exploration  will  give  little  definite  information  to  indicate 
what  surgical  procedure  should  be  followed,  even  after  palpation  and  electric 
examination.  The  surgeon  doing  early  exploration  will  do  best  to  leave 
this  group  alone.  He  should  reconstruct  the  field,  performing  a  careful  toilet, 
removing  scar  or  infolding  it,  or  surrounding  the  nerve  with  Ruber's  cargile 
membrane  to  prevent  scar  tissue  strangulation.  In  such  an  early  explora- 
tion he  can  then  atlord  to  withdraw  and  await  subsequent  events,  after  having 
carefuU}'  noted  the  anatomical  conditions.  In  the  remaining  two  groups 
the  indication  will  be  definite:  where  there  is  anatomical  interruption,  the 
nerve  must  be  sutured;  where  obviously  there  is  but  slight  injury,  the  nerve 
should  be  let  alone.  When  exploration  is  done  early,  many  cases  which 
might  not  have  gone  on  to  spontaneous  recovery  may  be  converted  into  recov- 
eries and  abortive  regeneration  changed  into  successful  regeneration  by  cor- 
recting the  field,  excision  of  scar,  liberation,  or  injection  of  salt  solution  into  the 
nerve — all  harmless  procedures  if  carefully  done,  which  cannot  impede  but  rather 
facilitate  regeneration.  Those  unfamiliar  with  the  finer  histology  of  nerve 
regeneration  may  be  tempted  to  be  radical  and  perform  nerve  suture,  failing 
to  appreciate  that  often  though  the  nerve  trunk  appears  damaged  neuraxes  may 
still  grow  down  through  it,  better  than  after  nerve  suture  with  its  greater 
dispersion  and  distortion  of  the  nerve  pattern. 

Considered  from  a  purely  anatomical  standpoint,  the  earlier  an  operation 
is  undertaken  the  less  difficult  it  is  to  do,  the  clearer  the  anatomical  field,  the 
better  the  operative  end  result  and  the  more  complete  the  recovery.  The 
longer  the  delay,  the  greater  is  the  amount  and  density  of  scar  tissue  and 
callus — the  nerve  ends  are  more  firmly  bound  and  fixed  in  a  retracted  position. 
In  early  operation  excision  of  the  nerve  need  be  very  limited  to  obtain  good 
nerve  ends.  Furthermore,  the  longer  the  delay  the  greater  are  the  secondary 
changes  in  the  muscles,  tendons  and  periarticular  structures. 

Factors  Interfering  with  Successful  Regeneration. — The  results  of  ner\e 
surgery  may  be  modified  by  a  great  variety  of  factors,  some  of  which  may  limit 
if  not  prevent  regeneration.  Delay,  even  for  a  long  time,  does  not  necessarily 
preclude  regeneration.  Katzenstein  (1913)  reports  successful  regeneration 
after  fourteen  years,  and  other  cases  have  been  described  in  which  the  interval 
has  been  more  than  three  years.  Generally,  with  an  interval  of  more  than  two 
years  the  end  results  are  not  favorable;  some  regeneration  takes  place,  but  the 


INDICATIONS    FOR    OPERATION  177 

degree  of  functional  return  is  less  than  from  early  suture.  When  the  lesion  in 
the  nerve  is  in  the  more  distal  portions — that  is,  farther  from  the  ventral  column 
cells — Stopford  (1920)  feels  that  a  long  interval  between  injury  and  operation 
is  decidedly  unfavorable  for  recovery;  while  if  the  lesion  is  in  the  more  proximal 
parts  of  the  nerve,  this  time  element  is  of  less  importance.  It  may  also  be  that 
the  more  peripheral  the  muscle  the  greater  its  functional  differentiation  and 
more  highly  specialized  movements  require  more  elaborate  and  more  accurate 
neural  impulses. 

The  bad  effect  of  a  long  interval  between  injury  and  operation  may  be 
lessened  by  thorough  and  continuous  massage  and  electricity  to  the  paralyzed 
muscles.  If,  on  the  other  hand,  circulation  and  nutrition  of  the  muscles  and 
the  free  mobility  of  the  tendons  and  joints  have  not  been  maintained,  marked 
regressive  changes  may  prevent  functional  return  even  after  successful  regener- 
ation. (See  Chapter  IX.)  If  delay  in  operation  is  caused  by  extensive  infection 
in  the  region  of  the  nerve  injury,  regeneration  may  be  limited  or  altogether 
prevented,  due  to  changes  in  the  nerve  trunk.  Infection  may  be  a  further  bar 
to  regeneration  when  the  resulting  neural  scar  tissue  is  too  extensive  to  allow  for 
suture  after  complete  excision  and  when  the  nerve  cannot  be  transplanted  into 
more  favorable  surroundings.  Sclerosis  of  the  nerve  may  occur,  due  to  prolifera- 
tion of  endoneural  and  perineural  connective  tissue,  and  other  interstitial 
changes  may  be  found,  particularly  in  partial  or  irritative  nerve  lesions. 

Ischemia  of  the  extremities,  due  to  coincident  injury  of  the  blood  vessels, 
may  seriously  interfere  with  regeneration.  It  is  not  known  whether  this  effect 
of  ischemia  is  exerted  on  the  nerve  trunk  itself  or  on  the  muscles  and  tendons, 
etc.  Probably  they  are  involved  together.  The  blood  vessels  of  nerves 
receive  collaterals  throughout  the  nerve  course,  so  that  if  this  collateral  supply 
be  absent  over  an  appreciable  extent  of  the  nerve  course  ischemia  may  have  its 
effect  upon  the  nerve. 

If  severed  nerves  be  embedded  in  scar  or  callus  at  a  point  at  which  mus- 
cular branches  are  given  off,  these  may  be  torn  from  the  nerve  trunk  or  may  be  so 
involved  by  scar  that  repair  is  impossible,  and  thus  their  muscle  groups  must 
remain  permanently  deprived  of  innervation  even  though  regeneration  takes 
place  in  the  remainder  of  the  nerve  trunk.  Poor  union  of  the  nerve  ends  may 
permit  only  a  relatively  small  degree  of  recovery,  because,  due  to  torsion  of  the 
nerve,  motor  neuraxes  may  be  directed  into  sensory  channels,  and  vice  versa, 
with  the  consequent  formation  of  only  a  small  number  of  motor  end  plates  with 


178         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

diminished  functional  restitution.  Functioning  nerve  endings  may  be  re-estab- 
lished it  is  true,  but  it  is  improbable  that  all  nerve  fibers  will  re-establish  their 
peripheral  connections  with  the  same  muscle  fibers  which  they  had  pre\'iously 
supplied  with  neuromuscular  or  neurotendinous  end  organs.  Hence  the 
reflex  mechanism  is  disturbed,  and  readjustment  of  the  impulses  within  the 
central  nervous  system  must  take  place,  with  re-education  of  nerve  centers. 
This  confusion  of  proprioceptive  impulses  (afferent  impulses  from  the  muscles, 
tendons,  and  joints),  due  to  distortion  in  the  nerve  pattern,  may  seriously 
interfere  with  co-ordinated  movements,  particularly  the  finer  movements  of  the 
hand,  which  diminishes  the  functional  value  of  motor  regeneration.  The 
patient  is  unable  to  estimate  the  exact  force  of  muscular  contractions  or  the 
precise  position  of  joints;  consequently  co-ordinated  movements  are  poorly 
performed.  Stopford  (1920)  has  also  called  attention  to  the  importance  of  this. 
"It  is  not  uncommon  to  discover,  after  suture  of  the  median,  that  all  the 
muscles-when  tested  individually — have  recovered  voluntary  power,  and  yet 
the  hand  is  of  slight  practical  service,  when  the  patient  attempts  purposive 
movements.  The  patient  will  often  volunteer  the  information  that  when  he 
attempts  to  work  he  finds  that  he  loses  the  grip  of  his  tools,  and  on  inquiry  it 
will  be  found  that  he  can  use  the  hand  fairly  well  as  long  as  he  concentrates 
upon  the  movements,  but  the  hand  ceases  to  function  satisfactorily  as  soon  as 
he  takes  his  eye  off"  it.  Such  patients  also  frequently  inform  you  that  the 
hand  is  useless  in  the  dark,  or  when  they  cannot  watch  what  they  are  trying 
to  do  with  it.  Such  complaints  may  be  heard  even  when  cutaneous  sensibility 
has  made  a  fair  recovery  and  all  the  muscles,  tested  individually,  exhibit 
voluntary  power.  It  seems  clear  that  such  a  disability  is  due  to  the  loss  of 
afferent  stimuli  from  joints,  muscles,  tendons  and  other  deep  structures.  It 
is  only  practicable  to  investigate  directly  the  recovery  of  fibers  conveying 
conscious  impressions  from  such  deep  structures  as  joints,  but  from  an  inves- 
tigation of  the  sense  of  posture  and  the  appreciation  of  passive  movements 
in  the  finger  and  thumb  articulations  supplied  by  the  nerve,  it  has  been  found 
that  these  were  generally  lost,  or  at  the  best  very  defective  even  when 
three  years  had  elapsed  since  the  time  of  the  suture.  It  would  seem  that  this 
is  very  important  to  remember  at  examinations  for  the  assessment  of  pensions 
after  nerve  suture  in  the  upper  limb,  since  the  routine  investigations  of  volun- 
tary power  and  cutaneous  sensibility  do  not,  in  themselves,  provide  sufficient 
information  to  determine  the  real  functional  capacity  of  the  hand.     It  is  also 


INDICATIONS    FOR    OPERATION  1 79 

an  awkward  problem  to  contend  with  during  the  later  stages  of  recovery  when 
muscle  re-education  becomes  of  greatest  importance,  since  it  provides  one  of 
the  main  obstacles  to  the  satisfactory  application  of  this  form  of  treatment — 
an  obstacle  which  is  probably  insufficiently  appreciated.  Previous  to  the  war 
our  chief  experience  of  muscle  training  was  derived  from  the  treatment  of 
infantile  paralysis,  and  consequently  many  who  are  responsible  for  the  super- 
vision of  this  form  of  treatment  are  content  merely  to  develop  an  increased 
range  of  movement  of  the  individual  muscles,  and  fail  to  realize  the  different 
problem  which  arises  in  peripheral  nerve  injury.  After  injuries  to  the  periph- 
eral nerves,  there  is  usually  a  serious  loss  of  those  afferent  stimuli  which 
are  of  such  importance  for  the  perfect  performance  and  adjustment  of  the 
liner  and  more  delicate  movements,  and  consequently  in  the  later  part  of  the 
treatment  every  effort  must  be  made  to  develop  those  purposive  and  more 
complex  movements  which  the  particular  patient  will  require  when  he  returns 
to  a  civil  occupation." 

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CHAPTER  IX 
MECHANICAL  TREATMENT 

The  problem  of  the  treatment  of  peripheral  nerve  injuries  does  not  begin 
nor  does  it  end  with  surgical  intervention.  The  treatment  of  these  cases 
requires  an  understanding,  not  only  of  the  operative  technic  and  indications, 
but  also  of  the  mechanical  and  postural  management  of  the  resulting  deformity 
as  well  as  of  the  mental  attitude  of  the  patient  toward  his  condition.  This 
mental  attitude  is  of  such  importance  that  it  cannot  be  overlooked  if  a  success- 
ful result  is  to  be  obtained.  In  no  other  field  of  surgery  must  the  patient  wait 
so  long  to  see  the  first  signs  of  improvement.  Hence  even  the  most  cheerful 
patients  become  discouraged  and  weaken  in  morale.  They  see  their  associates, 
though  apparently  more  seriously  injured  leave  the  hospital  recovered,  while  their 
own  condition  remains  practically  unchanged.  In  civil  life  among  the  indus- 
trial injuries,  the  average  patient  finds  it  difficult  to  understand  why  improve- 
ment is  not  as  apparent  in  the  rest  of  the  extremity  as  in  the  superficial  wound. 
The  development  of  complications,  such  as  traumatic  ulcers  and  other 
cutaneous  regressive  changes,  causes  further  discouragement.  To  obviate  this 
constant  eft'ort  should  be  devoted  to  the  re-education  and  use  of  the  paralyzed 
muscles,  especially  in  the  early  stages  of  regeneration.  The  patient  must  not 
be  allowed  to  become  resigned  to  his  disability  nor  to  lose  the  will  to  regain 
control  of  the  part,  thus  superimposing  on  the  underlying  organic  injury  an 
element  of  functional  disorder  many  times  more  difilcult  to  handle  than  the 
original  nerve  injury  itself. 

However  skillfully  surgical  interference  may  have  removed  all  obstacles 
to  downgrowth  of  neura.xes,  the  return  of  motor  function  may  not  take  place 
unless  comprehensive  preoperative  and  postoperative  treatment  has  been 
given.  The  aim  of  such  treatment  is  to  prepare  the  paralyzed  parts  so  that 
when  nerve  regeneration  and  neurotization  is  completed  return  of  function  may 
not  be  prevented  by  mechanical  obstacles.  One  such  obstacle  may  be  met 
with  in  the  paralyzed  muscles  themselves,  undergoing  marked  regressive 
changes  due  to  loss  of  innervation,  which  may  be  hastened  and  rendered 
more  severe  as  a  result  of  poor  nutrition  and  overstretching.  When  the  nerve 
lesion  has  been  incomplete  and  neuritis  is  present,   the  muscles  may  show 

183 


1 84         SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 

severe  fibrosis.  Another  obstacle  to  return  of  function  may  also  be  encoun- 
tered in  the  antagonist  muscles,  which  untreated  posturally  undergo  adaptive 
shortening  causing  permanent  contraction  with  limitation  in  the  range  of 
motion.  If  concomitant  bony  injuries  are  present  free  mobility  may  be 
interfered  with  by  callus  or  angulation  and  faulty  ahgnment. 

The  purpose  of  mechanical  treatment  is  to  assist  in  maintaining  the  nutri- 
tion of  the  part,  to  prevent  overstretching  of  the  paralyzed  muscles  or  their 
contraction,  to  restrict  adaptive  shortening  of  the  antagonists  and  to  maintain, 
as  near  as  possible,  the  normal  range  of  motion  within  the  tendon  sheaths 
and  the  joints. 

CUnically  it  has  long  been  recognized  that  when  a  muscle  has  been  con- 
stantly overstretched,  contractility  may  not  return,  or  may  be  greatly  delayed, 
in  spite  of  the  fact  that  the  nerve  injury  itself  has  been  repaired  by  satisfactory 
downgrowth  of  neuraxes.  Many  times  it  has  been  found  in  the  treatment  of 
anterior  poliomyelitis  that  paralyzed  muscles  which  have  been  overstretched, 
due  to  lack  of  postural  treatment,  may  show  a  return  of  motor  function  when 
nothing  more  has  been  done  than  to  correct  the  postural  deformity  thus  pre- 
venting further  overstretching.  Neurotization  alone,  though  complete,  may  be 
unable  to  bring  about  a  return  of  contractility.  Uncorrected  postural  deform- 
ity with  constant  overstretching  of  paralyzed  muscles,  clinically  at  least,  causes 
more  permanent  loss  of  contractility  and  more  marked  regressive  changes  than 
where  postural  deformity  has  been  prevented.  Thus,  from  a  clinical  standpoint, 
the  first  cardinal  principle  of  mechanical  treatment  of  peripheral  nerve  in- 
juries is  to  obtain  relaxation  of  the  paralyzed  muscles  and  to  prevent  their 
overstretching. 

Unfortunately  there  has  been  very  little  experimental  work  to  determine 
the  influence  of  constant  overstretching  and  other  mechanical  factors  on  the 
recovery  of  paralyzed  muscles.  In  the  usual  experimental  animals,  it  seems  to 
me  extremely  doubtful  if  the  mechanical  conditions  affecting  the  paralyzed 
muscles  can  be  compared  to  those  found  in  the  human,  for  there  is  too  great  a 
difference  in  the  posture  and  anatomical  arrangement  of  the  extremity.  This 
disparity  is  essentially  one  of  mechanics,  due  to  the  assumption  of  plantegrade 
locomotion  and  the  upright  stature.  Consequently,  while  animal  experiments 
to  test  overstretching,  may  throw  some  light  upon  the  question  they  cannot 
be  considered  definitely  conclusive.  However,  experimentally,  depriving  a 
muscle  of  its  nerve  supply  has  yielded  other  valuable  information  clinically 
applicable. 


MECHANICAL  TREATMENT  185 

Changes  in  Denervated  Muscle. — The  relation  of  the  muscle  to  its  nerve 
apparently  varies  according  to  the  stage  of  development  of  the  muscle.  Once 
the  neuromuscular  connection  has  been  established,  the  muscle  fiber  appears 
to  be  entirely  dependent  upon  the  nerve  for  its  integrity.  Denervated  muscle 
begins  to  undergo  degeneration  immediately;  the  degeneration  varies  in  degree 
in  proportion  to  the  length  of  time  the  muscle  is  deprived  of  its  nerve  supply. 
The  muscle  gradually  regresses  in  late  stages,  and  assumes  the  appearance  of 
embryological  tissue  from  which  muscle  developed.  At  the  other  end  of  the 
nerve  fiber  a  similar  regressive  change  takes  place  in  the  nerve  cell  and  it 
tends  to  assume  the  appearance  of  the  neuroblast — the  embryonal  cell  from 
which  the  nerve  cell  developed.  Thus  it  would  appear  that  when  these  two 
tissues,  morphologically  highly  specialized  and  metabolically  extremely  ac- 
tive, are  prevented  from  functioning  they  revert  to  more  simple  fetal  forms 
which  the  organism  can  maintain  with  less  effort. 

This  complete  dependence  of  the  adult  muscle  fiber  on  its  nervt  supply 
is  all  the  more  interesting  since  Harrison's  (1904)  experimental  studies  have 
shown  that  in  anervated  fetal  muscle  not  only  does  differentiation  of  the  muscle 
fiber  occur,  but  also  that  differentiation  into  muscle  bundles,  having  normal 
attachments  and  tendons,  takes  place.  Harrison  found  that  by  removal  of 
the  spinal  cord  in  larva;  of  the  frog  before  differentiation  of  either  nerve  or 
muscle  tissue  had  begun  that  muscular  difi'erentiation  went  on  nonnally  and 
that  the  nerve  element  exerted  no  controlling  influence  on  the  morphogenesis 
of  the  muscle  fiber.  The  older  view  that  muscle  differentiation  did  not  occur 
in  the  absence  of  neurotization  is  thus  contradicted.  Such  muscular  independ- 
ence is  further  indicated  by  Bardeen  (1900)  Lewis  (1901),  who  found  that  in 
the  pig  embryo  and  also  in  the  human,  muscular  dift"erentiation  is  fairly  well 
advanced  before  neuromuscular  connections  are  made.  With  such  inherent 
power  of  independent  differentiation  in  muscle  fiber,  it  seems  all  the  more 
strange  that,  following  the  establishment  of  neuromuscular  connections, 
the  muscle  fiber  thenceforth  should  become  dependent  on  the  nerve  supply  not 
only  for  its  integrity  of  function  but  for  its  structure  as  well. 

Physiological  Changes. — The  reaction  of  degeneration  is  not  found  in 
muscles  until  after  degeneration  of  the  "  receptor  "  or  postneural  substance  which 
does  not  take  place  in  the  early  stages  of  denervation.  PatonandFindlay  (1916) 
found  that  curare  in  doses  sufficient  to  inhibit  muscle  response  to  direct  stimu- 
lation in  normal  muscles  also  inhibited  such  response  in  freshly  denervated 
muscles  after  two  or  three  days,  at  a  time  when  the  muscle  was  still  excitable 


1 86         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

mechanically,  but  not  by  the  faradic  current.  In  denervated  muscle  of 
longer  standing  when  the  reaction  of  degeneration  appears,  curare  has  no 
inhibitory  effect.  These  observations  show  that  the  postneural  or  "receptor 
substance"  degenerates  later,  secondarily  to  the  motor  nerve  endings.  These 
authors  thought  that  the  reaction  of  degeneration  "may  be  a  result  of  degen- 
eration of  the  'receptor  substance"."  Boeke  (1921)  believes  that  the  mor- 
phological basis  of  this  "receptor  substance"  is  the  "periterminal  network" 
seen  in  the  motor  end  plate  as  a  delicate  network  between  the  neurofibrillar 
end  ramifications  and  the  sarcoplasm.  In  early  stages  of  degeneration  the 
"periterminal  network"  may  still  be  seen  after  the  neurofibrils  are  broken 
up. 

During  the  time  the  muscle  is  without  its  nerve  supply,  it  constantly 
shows  line,  fibrillary  twitching,  rhythmic  in  character  (Schiff,  1851),  (Langley 
and  Kato,  191 5).  I  have  seen  constant  fibrillary  twitchings  in  the  tongue 
musculature  following  section  of  the  hypoglossal  nerve  persist  for  fifteen  years. 
As  a  result  of  more  recent  experiments  Langley  concluded  that  it  was  possible 
that  constant  fibrillation,  without  sufficient  periods  of  rest,  prevented  the 
anabolic  processes  from  equalizing  the  catabolic.  The  atrophy  of  denervated 
muscle  may  not  only  be  due  to  such  metabolic  inecjuality,  but  possibly  also 
to  extreme  fatigue,  the  result  of  constant  fibrillation.  The  amount  of  atrophy 
corresponds  largely  to  the  degree  of  fibrillation.  However,  he  was  unable 
to  determine  whether  the  fibrillation  was  the  resultant  or  the  cause  of  the 
atrophy. 

The  great  increase  in  the  oxygen  use  of  the  denervated  muscle  over  normal 
shows  that  catabolic  processes  are  markedly  increased  (Langley  and  Itagaki, 
IQ17).  Not  only  is  there  an  increase  in  the  breaking  down  of  the  muscle  fiber 
in  denervated  muscle,  but  there  is  also  a  decrease  in  the  power  of  repair, 
shown  by  the  fact  that  denervated  muscle  cannot  be  made  to  increase  in  size 
by  contractions  artificially  induced  over  a  long  period  of  time.  That  a  denerv- 
ated muscle  is  a  fatigued  muscle  is  further  evidenced  by  its  lowered  specific 
gravity  (Langley),  for  as  was  shown  by  Bancroft  and  Kato  (1915)  fatigued 
muscle  has  less  specific  gravity  than  unfatigued. 

MECHANICAL  TREATMENT 

The  importance  of  correcting  postural  deformities  and  preventing  constant 
overstretching,  though  thus  far  unsupported  experimentally,  has  been  generally 
appreciated  in  peripheral  nerve  centers  where  those  cases    which  have  been 


MECHANICAL   TREATMENT  1 87 

untreated  show  varying  degrees  of  deformity,  even  total  irreducible  contract- 
ures and  mal-positions.  The  need  for  mechanical  treatment  has  been  clearly 
indicated  by  the  reports  of  all  peripheral  nerve  centers,  some  showing  that  in 
fully  fifty  ])er  cent  of  the  cases  reporting  for  physio-therapy  deformities  might 
have  been  avoided  by  proper  splinting  and  by  surgical  interference  not  too  long 
delayed. 

Many  of  the  earlier  appliances  attempted  to  correct  postural  deformity 
and  overstretching  without  replacing  a  part  of  the  mo\-ement  lost.  It  must 
be  recalled  that  not  only  should  the  elasticity  and  extensibility  of  the  muscles 
be  preserved  as  far  as  possible,  but  also  the  normal  mobility  of  the  tendons  and 
joints  which  these  muscles  move.  In  the  fixed  type  of  apparatus,  the  tendons 
and  joints  themselves  become  fixed,  unless  special  attention  is  paid  to  maintain- 
ing mobility  within  the  normal  range  of  motion.  Stookey  (1918)  and  others 
have  pointed  out  that  "immobilization  alone  or  mobilization  alone  docs  not 
prevent  contracture.  Efficient  immobilization  must  be  combined  with  efficient  mobili- 
zation. "  All  movements  should  be  regularly  performed  and  the  periods  of 
repose  guarded  by  apparatus. 

The  Ideal  Apparatus. — This  should  be  light,  simple,  easily  applied  and 
removed,  should  immobilize  no  more  than  is  necessary,  and  be  inexpensive  as 
well  as  inconspicuous.  Furthermore,  the  apparatus  must  treat  the  total 
deformity — not  merely  one  of  the  apparent  faulty  positions.  On  the  other 
hand,  an  apparatus  should  not  attempt  to  correct  deformities  which  do  not 
exist;  for  example  to  try  to  support  the  palmar  arch  in  musculospiral  injuries  is 
uncalled  for,  since  the  muscles  supplied  by  this  nerve  do  not  affect  the  integrity 
of  the  palmar  arch.  In  so  far  as  possible,  the  straps  should  be  placed  so  as  to 
rest  upon  the  tendinous  parts  and  not  constrict  muscle  bellies.  Great  caution 
must  be  taken  to  avoid  pressure  sores,  particularly  in  those  cases  in  which  an 
effort  is  being  made  to  overcome  rigid  contractures,  since  it  must  be  remembered 
that  there  may  be  anesthesia,  not  only  of  the  superficial  parts  but  also  of  the 
deeper  structures;  thus  the  warning  usually  given  by  pain  is  not  present.  All 
splints  removed  at  night  should  be  replaced  by  other  apparatus  more  com- 
fortable and  approximately  as  efficient. 

Appliances  of  the  more  complicated  types,  such  as  those  used  for  plexus 
injuries  and  Thomas  splints  in  anterior  crural  nerve  injuries,  etc.,  should  be 
specially  made  for  each  individual  case.  Only  general  principles  of  mechanical 
treatment  of  these  injuries  will  be  outlined  here.  The  treatment  of  the  more 
distinct  types  of  peripheral  nerve  injuries  will  be  treated  separately,  except  in 


1 88         SURGICAL    AXD    MECHANICAL    TREATMENT    OF    PERIPHER.AL    NERVES 

those  instances  in  which  associated  paralyses  may  be  similarly  handled. 
Combined  and  multiple  injuries  are  variable  and  -n-ill  require  modified  types  of 
apparatus  for  each  case.  Modification  should  be  made  whenever  expedient, 
with  alterations  and  changes  according  to  the  stage  and  progress  of  the  paralysis. 
The  spKnt  should  be  made  to  fit  the  indi\-idual  and  not  the  indi^^dual  or  injury 
the  splint. 

Early  Mechanical  Treatment. — The  mechanical  management  of  peripheral 
nerve  injuries  ma}-  be  divided  into  the  immediate  and  the  subsequent  treatment. 
The  former  includes  the  first  few  weeks  until  the  associated  injuries  have  pro- 
gressed far  enough  to  permit  of  definite  treatment  directed  toward  the  nerve 
lesion.  The  early  management  of  these  cases  will  depend  very  largely  upon  the 
coincident  injuries.  However,  given  a  case  in  which  the  nerve  injuries  alone 
predominate,  that  is,  without  tendon  or  bony  injuries,  the  extremity  should  be 
placed  according  to  Stofi'el  (1915)  so  that  the  severed  nerve  ends  may  be  brought 
in  as  close  proximity  as  possible  and  held  there  for  a  few  weeks,  during  which 
time  the  nerve  ends  will  become  anchored  and  a  more  relaxed  position  maj' 
then  be  assumed. 

This  is,  in  practice,  apptying  to  nerve  injuries  the  principles  long  in  usage 
for  muscle  and  tendinous  lesions.  In  nerve  injuries,  such  considerations  are  of 
questionable  value,  since  after  the  immediate  retraction  of  the  nerve  ends  at  the 
time  of  severance  further  shortening  does  not  take  place  as  in  the  case  of 
injuries  to  tendons  and  muscles.  In  these ,  contraction  of  muscle  bellies  is 
followed  by  further  puUing  apart  of  the  tendon  ends.  A  severed  nerve  tends 
to  assume  immediately  a  definite  position  and  to  keep  it,  being  held  more  or  less 
firmly  in  place  b}-  the  fascial  layers  which  intimately  surround  the  nerve  trunk. 

The  position  in  which  the  limb  is  to  be  maintained  will  depend  not  only  on 
the  nerve,  but  also  on  the  level  of  the  lesion. 

Upper  Extremity.  Lesions  Above  the  Elboic. — In  injuries  to  the  median, 
musculocutaneous  and  musculospiral  nerves  in  the  upper  arm,  the  arm  should  be 
adducted  and  the  forearm  acutely  flexed;  in  injuries  to  the  ulnar  nerve  in  the 
same  region  the  arm  is  also  adducted  but  the  forearm  is  extended. 

Lesions  Below  the  Elbow. — In  injuries  to  the  median  nerve  at  this  level  the 
forearm  is  flexed  to  a  right  angle,  supinated  and  the  hand  acutely  flexed  at  the 
wrist;  in  lesions  of  the  posterior  interosseous  nerve  the  forearm  is  held  in  the 
same  position,  except  that  the  hand  is  fully  extended  dorsally,  while  in  injuries 
to  the  ulnar  nerve  the  forearm  is  extended,  the  hand  adducted  and  held 
in  fle.xion. 


MECHANICAL    TREATMENT  1 89 

Lower  Extremity.  Lesions  Above  iJie  Knee. — In  injury  to  the  sciatic  nerve 
in  this  region  the  thigh  is  held  extended  and  the  leg  flexed  upon  the  thigh. 
By  extension  of  the  thigh  the  central  end  of  the  sciatic  nerve  is  relaxed,  and 
the  distal,  by  flexion  of  the  leg  upon  the  thigh.  When  the  injury  is  below  the 
middle  third  of  the  thigh  flexion  of  the  leg  alone  generally  will  be  sufficient  and 
extension  of  the  thigh  on  the  trunk  is  not  necessary.  In  lesions  of  the 
anterior  crural  nerve  the  thigh  is  flexed  upon  the  trunk. 

Lesions  Below  the  Knee. — Little  is  gained  by  position  in  this  region,  especially 
when  the  anterior  tibial  or  musculocutaneous  is  involved.  However,  in  the 
posterior  tibial  2  to  3  cm.  may  be  gained  by  flexion  of  the  knee  and  plantar 
flexion  of  the  foot. 

When  other  injuries,  particularly  fractures,  exist  with  the  nerve  injury  it  is 
needless  to  say  that  the  primary  indication  so  far  as  position  of  the  limb  is 
concerned  is  to  treat  the  fracture  so  as  to  avoid  any  permanent  deformity. 

Late  Mechanical  Treatment. — Correction  of  Deformities  Before  Operation. — 
During  the  early  period  of  treatment  the  injury  is  treated  both  with  a  view  to 
relax  the  paralyzed  muscles  and  the  severed  nerve  ends,  while  in  the  later 
stages  the  nerve  ends  having  become  fixed  no  longer  need  be  considered, 
attention  being  directed  in  this  stage  to  the  position  of  the  paralyzed  muscles. 
Prior  to  operative  interference  in  nerve  injuries,  it  is  desirable  to  obtain  as  free 
mobility  in  the  paralyzed  parts  as  is  possible,  so  that  sufficient  flexion  or  exten- 
sion to  bring  the  nerve  ends  in  apposition  may  be  obtained. 

Contractures  and  adhesions  should  be  stretched  gradually  by  continuous 
and  not  by  interrupted  force.  Continuous  and  gradual  stretching  is  better  than 
daily  forcible  movements,  since,  when  such  movements  are  of  sufficient  force  to 
increase  mobility,  the  fibrous  tissue  is  torn  and  a  new  fibroblastic  reaction  is 
set  up  which  serves  to  increase  the  amount  of  scar.  Gradual  breaking  up  of 
adhesions  induces  less  tissue  reaction  and,  therefore,  is  more  permanent  in  its 
effect.  In  some  cases  it  may  be  necessary,  at  first,  to  break  up  adhesions  under 
ether  and  to  continue  the  treatment  by  application  of  such  appliances  as  exert 
constant  and  increasing  stretching.  It  is  well  to  remember  that  in  extensive 
paralysis  of  long  duration,  the  bones  may  become  brittle,  little  force  being 
required  to  produce  fracture,  so  that  perhaps  only  those  experienced  with  such 
conditions  may  care  to  undertake  this  method  of  treatment. 

Contractures  of  neuritic  origin,  perhaps  more  than  others,  are  the  most 
difficult  to  handle,  since  immobility  may  only  serve  to  accentuate  the  deformity; 
the  contractures  recurring  within  a  few  days  after  removal  of  the  appliance. 


1 90         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

On  the  other  hand,  if  these  injuries  are  left  untreated  postural  disability  is 
certain  to  become  worse.  The  choice  seems  to  be  the  lesser  of  two  evils.  In 
such  cases,  daily  movements  and  baths  with  electricity  must  be  combined  with 
immobilization.  In  the  earlier  stages  of  neuritic  contracture,  the  muscle 
groups  show  marked  hypertonia,  with  beginning  tenderness  of  the  muscle 
bellies  and  gradual  increasing  deformity  which  may  be  overcome  by  skillfully 
planned  movements.  In  the  later  stages,  the  tenderness  becomes  marked,  and 
the  muscles  extremely  sensitive  to  all  mechanical  stimuli.  The  slightest  effort 
throws  the  muscles  into  extreme  contraction,  almost  in  a  tetanic  spasm.  The 
phases  of  relaxation  are  shorter  and  shorter  until  they  are  practically  lost,  the 
muscle  becoming  so  rigid  that  even  passive  movements  are  impossible.  In  these 
cases  the  effort  mechanically  is  to  overstretch  the  muscles  so  that  for  the  time 
being  all  power  of  contraction  is  lost.  Positive  splinting,  combined  with  con- 
trast baths  as  well  as  sinusoidal  electricity  in  a  hot  paraffine  medium,  will  be 
found  serviceable  in  some  but  not  all  cases. 

Time  to  Change  Position  of  Extremity  After  Operation. — When  it  has  been 
necessary  to  fix  the  extremity  in  an  abnormal  position  to  bring  nerve  ends 
together  the  question  of  when  the  normal  attitude  may  again  be  assumed 
must  be  met.  It  has  been  customary  to  maintain  the  extremity  in  its  post- 
operative position  for  four  to  six  weeks  returning  gradually  thereafter  to 
normal.  Within  this  period  union  between  the  nerve  ends  will  have  become 
firm  and  the  neuraxes  from  the  central  stump  should  have  gained  the  distal. 
There  is  some  evidence  to  indicate  that  union  is  sufficiently  firm  much  earlier 
and  hence  motion  may  be  begun  sooner.  In  a  few  secondary  operations  follow- 
ing nerve  suture  it  has  been  shown  that  union  between  the  nerve  ends  is  com- 
paratively firm  within  a  period  of  ten  days  or  before.  In  one  case  reported 
by  Babcock  (19T9)  the  patient  removed  the  sphnt  during  the  first  few  days 
after  operation,  necessitating  secondary  exploration  of  the  nerve.  The  line 
of  suture  of  the  sciatic  nerve  was  unaltered  and  no  separation  of  the  nerve 
ends  had  occurred  in  spite  of  the  change  in  the  position  of  the  limb.  Possibly 
such  early  firm  union  as  this  is  made  possible  by  exact  apposition  of  the  nerve 
ends  and  numerous  fine  sutures  which  unite  the  epineurium. 

If  the  nerve  has  been  freely  mobilized  both  centrally  and  distally,  or 
stretched,  a  connective  tissue  reaction  is  often  set  up  in  the  tissue  surrounding 
the  nerve.  The  nerve  becomes  fixed  in  its  bed  and  is  held  in  a  more  or  less 
continuous  splintage  by  fine  fibrous  bands  over  a  considerable  portion  of  its 
course.     Unless  adhesions  are  prevented  by  early  movements  the  mobility  of 


MECHANICAL    TREATMENT  IQI 

the  nerve  in  its  bed  may  be  impaired;  the  longer  the  fixation  after  suture 
the  tirmer  the  nerve  is  held.  Mobility  within  the  nerve  bed  is  essential  to 
allow  free  motion  of  the  extremity  without  injury  to  the  nerve. 

In  several  instances  in  which  secondary  operations  were  performed  follow- 
ing nerve  transposition  it  was  surprising  to  find  the  nerve  fixed  in  its  new 
bed  by  numerous,  fine  bands  from  the  surrounding  connective  tissue  with  hardly 
any  movement  present.  Even  attempts  to  move  the  exposed  nerve  directly 
were  unsuccessful,  so  tight  was  the  adhesion.  Because  of  this  possibility, 
motion  should  be  begun  as  soon  as  nerve  union  is  firm,  following  the  prac- 
tice applied  to  other  structures  where  fixation  is  to  be  avoided.  Hence,  motion 
after  suture  must  not  be  too  long  delayed,  nor  begun  too  early  before  connec- 
tive tissue  union  of  the  nerve  ends  takes  place. 

In  view  of  these  facts  one  should  begin  to  lower  the  limb  about  ten  days 
to  two  weeks  after  suture,  gradually  increasing  the  range  of  motion  so  that 
within  three  or  four  weeks  a  normal  or  nearly  normal  position  may  be  assumed. 
In  cases  in  which  the  fixation  position  has  been  extreme  a  longer  period  may  be 
needed  to  reach  the  normal. 

Associated  Treatment. — Besides  mechanical  treatment  of  nerve  injuries, 
additional  measures  remain  to  help  maintain  the  nutrition  and  mobility  of  the 
paralyzed  extremity.  These  measures  are  massage,  electricity  and  re-educa- 
tion. Unfortunately,  it  is  not  possible  to  discuss  in  detail  in  this  volume  these 
forms  of  treatment.  They  are  extremely  important  and  should  be  given  by 
those  who  are  fully  familiar  with  their  possibilities. 

To  advise  massage  and  electricity  is  insufficient  unless  specific  instructions 
are  given.  Frequently  patients  referred  for  consultation  will  tell  you  that 
they  have  been  given  electricity,  but  that  it  has  done  them  no  good,  and  the 
limb  would  apparently  indicate  this.  However,  upon  further  inquiry  it  will  be 
found  that  only  the  faradic  current  had  been  used,  which  of  course  is  useless 
in  denervated  muscles.  The  heartiest  co-operation  between  the  surgeon  and 
the  physiotherapist  is  essential. 

The  purpose  of  both  massage  and  electricity  in  denervated  muscle  is  to 
improve  the  nutrition  and  aid  in  the  removal  of  waste  products,  as  well  as  to 
assist  in  the  maintenance  of  the  usual  mobility  of  tendon  sheaths  and  joints,  so 
that  peripheral  obstacles  to  resumption  of  function,  following  successful 
regeneration,  may  not  be  encountered. 

Massage  and  Baths. — There  seeins  to  be  some  experimental  evidence  to  the 
efTect  that  massage  is  only  of  the  slightest    benefit    in  preventing  atrophy 


192  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

(Langley  and  Hashimoto,  1918).  To  prevent  atrophy  is  not  the  purpose  of  mas- 
sage, but  rather  to  improve  the  circulation  and  mobihty.  It  has  aheady  been 
pointed  out  that  denervated  muscle  shows  an  excess  of  waste  products,  and  the 
object  of  massage  is  to  increase  the  circulation  so  as  to  remove  the  excessive 
waste  and  increase  the  supply  of  new  blood  and  lymph.  The  lightest  forms  of 
massage  are  indicated;  due  to  the  extreme  atrophy  of  the  paralyzed  muscle  pres- 
sure may  be  transmitted  to  the  blood  vessels  and  heavy  massage  may  cause  para- 
lytic dilatation  thus  defeating  the  end  sought.  This  objection,  perhaps,  is 
more  theoretical  than  practical.  Of  the  different  forms  of  baths,  perhaps  none 
is  better  than  contrast  bathing.  The  extremity  is  placed  alternately  in  hot 
and  cold  water,  thus  increasing  the  vasomotor  tone  and  the  circulation.  The 
whirlpool  baths  have  distinct  advantages,  since  not  only  may  the  benefits  of  the 
hot  bath  be  supplied,  but  also  a  massage  eff'ect  as  well. 

Electrical  Treatment. — This  form  of  treatment  obviously  varies  according 
to  the  stage  of  the  injury.  During  the  time  that  nerve  impulses  do  not  reach 
the  muscle,  naturally  the  faradic  current  is  of  no  value.  The  advantages  of  the 
galvanic  current  were  very  early  appreciated.  Brown-Sequard  (1859)  believed 
that  this  current  improved  the  condition  of  the  muscle,  both  by  contraction  and 
by  some  direct  action  on  its  metabohsm.  Muscle  deprived  of  motor  end  plates 
is  inhibited  by  the  chemical  effects  of  its  waste  products  and  these  are  removed 
through  the  increased  circulation  produced  by  the  galvanic  current.  This 
action  is  especially  true  of  the  sinusoidal  current,  which  improves  the  nutrition 
and  the  circulation,  in  spite  of  the  fact  that  contraction  of  the  muscle  is  not 
possible.  A  contraction  of  muscle  during  atrophy  is  not  necessarily  beneficial, 
but  it  is  rather  the  result  of  the  contraction,  wliich,  as  we  know  increases  the 
nutrition  and  betters  the  circulation  with  attendant  removal  of  waste  pro- 
ducts. In  fact  those  factors  which  increase  the  circulation  without  contrac- 
tion are  perhaps  more  desirable  since  contraction  entails  an  added  expenditure 
of  energy  and  an  increase  in  waste  products.  This  end  is  accomplished  by  both 
massage  and  electricity — probably  each  in  a  different  manner,  since  I  have 
repeatedly  seen  cases  receiving  either  one  or  the  other  form  of  treatment 
markedly  benefitted,  so  far  as  the  general  appearance  of  the  extremity  was 
concerned,  by  the  addition  of  either  massage  or  the  sinusoidal  current. 

Electrical  baths  have  been  objected  to  by  some  on  the  grounds  that  they 
may  cause  overaction  of  the  sound  muscles  with  corresponding  overstretching 
of  the  paralyzed.  This  objection  may  be  readily  avoided  by  the  application 
of  the  current  according  to  the  method  of  Lapicque  (1915)  and  based  on  the 


MECHANICAL   TREATMENT  193 

chronaxia.  Lapicque  at  first  evolved  this  method  as  a  means  of  testing  muscles, 
so  as  to  obtain  isolated  contraction  without  the  confusing  element  of  dispersion 
and  masking  of  the  reaction  by  contracion  of  the  neighboring  sound  muscles. 

An  electrical  stimulus  has  both  a  minimal  strength  below  which  it  will  not 
produce  contraction,  no  matter  how  long  applied,  and  also  a  minimal  duration 
below  which  time,  no  matter  how  strong  the  current,  it  will  not  cause  contraction. 
By  determining  the  minimal  threshold  of  excitation  (usually  doubled  in  calcula- 
tions) and  then  the  minimal  duration  with  which  this  strength  current  will 
produce  a  contraction  the  chronaxie  is  determined.  The  chronaxie  in  normal 
muscle  is  about  one-thousandth  second  while  that  of  a  paralyzed  muscle  one- 
hundredth  second  or  more.  In  this  manner  the  current  may  be  applied  so 
that  the  chronaxie  of  the  sound  muscle  is  passed  before  its  threshold  of 
excitation  is  reached,  while  the  current  is  supplied  to  the  paralyzed 
muscle  so  that  the  minimal  threshold  of  the  paralyzed  muscle  is  reached 
at  its  exact  chronaxie.  By  this  means,  a  response  may  be  obtained  only 
in  the  paralyzed  muscles  without  danger  of  contraction  of  any  of  the  neighboring 
muscle  groups.  This,  of  course,  is  apphcable  only  as  long  as  the  muscle  still 
shows  electrical  response  or  at  a  time  when  regeneration  is  taking  place.  The 
application  of  this  principle  of  Lapicque  has  meant  a  great  advance  both  in 
muscle  testing  and  in  the  possibilities  of  the  application  of  electricity  to  para- 
lyzed muscles. 

Treatment  of  Denervated  Muscle  During  Stage  of  Recovery. — The 
questions  which  have  arisen  in  regard  to  the  advisability  of  the  application  of 
electricity  to  paralyzed  muscles  unable  to  respond  to  electricity  do  not  apply  to 
those  patients  whose  nerves  are  regenerating.  Some  form  of  electricity 
is  advised  by  most  workers.  The  question  arises,  however,  as  to  the  strength 
of  and  the  time  at  which  the  current  should  be  applied.  It  is  held  that  it 
might  be  dangerous  to  pass  an  electrical  current  through  a  young  regenerating 
nerve  fiber  and  also  that  the  contraction  obtained  might  be  injurious  to  the 
regenerating  muscle.  Unfortunately,  there  are  no^experimental'data  of  which 
I  am  aware  dealing  with  this  question.  In  my  own  experience  I  have  tended 
to  be  rather  conservative  and  prefer  to  wait  until  the  regeneration  is  fairly  well 
advanced  before  advising  the  application  of  the  faradic  current,  on  the  ground 
that  to  delay  will  do  no  harm  either  to  the  muscle  fiber  or  to  the  nerve. 

Re-education. — No  more  important  factor  of  treatment  in  the  stage  of 
regeneration  can  be  initiated.  The  aim  should  be  not  only  to  increase  the 
range  of  motion,  as  for  example  is  done  in  infantile  paralysis,  but  also  to 


194         SURGICAL    AND    MECHANICAL     TREATMENT    OF    PERIPHERAL    NERVES 

re-educate  the  proprioceptive  paths  (bone,  joint,  tendon  and  muscle  sense). 
These  paths  may  be  seriously  damaged,  due  to  distortion  of  the  sensory  fibers 
and  also  to  errors  arising  as  a  result  of  injury  of  the  motor,  so  that  the  normal 
reflex  paths  essential  for  synergic  action  are  often  lost.  To  have  such  action 
the  same  group  of  ventral  column  cells  must  innervate  the  same  muscle  or 
muscle  groups — a  probability  rather  remote  following  nerve  suture.  Thus  in 
paralysis  of  peripheral  nerve  origin,  the  ajferent  as  well  as  the  efferent  functions 
of  the  nerve  are  in  need  of  re-education;  thereby  differing  materially  from 
paralysis  of  anterior  poliomyelitis  in  which  only  the  efferent  paths — and  these 
often  only  partially — are  destroyed. 

This  problem  of  re-education  is  of  great  importance,  for  while  the  individual 
muscle  may  regain  its  power  of  contraction,  its  more  delicate  functions  may  be 
lost  with  its  proprioceptive  sense  seriously  impaired.  This  has  been  found  to 
be  a  serious  source  of  disability  and  this  point  must  be  considered  by  pension 
boards  in  determining  the  amount  of  pension  as  well  as  by  industrial  compensa- 
tion commissions  in  civil  life. 

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Arch.  Neurol.  &  Psychiat.,  v.  3:  Feb.,  1920,  p.  151. 
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action  of  massage.  Arch.,  Radiol.  &  Electroth.,  v.  23:   1918-1919,  p.  59. 
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pp.  145-160. 
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developing  musculature  in  the  embryo  of  the  frog.  Am.  Jour.  Anat.,  v.  3:   1904,  p.  197., 
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massage,  Jour. Physiol,  v.  53:  1919,  p.  92-116 
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v.  51:  1917,  p.  202. 


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CHAPTER  X 
FACIAL  NERVE 

Probably  there  is  no  musculature  more  essential  to  the  happiness  of  the 
individual  than  the  facial  musculature.  Facial  paralysis  when  unrelieved 
offers  ^to  the  neuro-surgeon  a  therapeutic  field  of  great  significance,  but 
when  the  divided  facial  nerve  fails  to  regenerate  spontaneously  operative 
possibilities  are  necessarily  limited.  Anatomically  there  are  but  two  motor 
nerves  in  the  neighborhood  of  the  facial  which  can  be  used  lor  nerve  crossing. 
Faure  and  Furet  (1898)  first  performed  spinofacial  crossing  and  Korte  (1901) 
hypoglossofacial.  Both  of  these  methods  give  some  degree  of  motor  return 
and  an  improvement  in  the  facial  symmetry  during  repose,  but  are  accompa- 
nied by  associated  movements  in  conjunction  with  the  movements  of  the  neck 
and  shoulder,  or  of  the  tongue  which  tend  to  vitiate  the  excellence  of  the  func- 
tional results. 

Mannasse  (1900)  was  the  first  to  test  experimentally  implantation  of  the 
distal  segment  of  the  facial  nerve  into  the  spinal  accessory  and  obtained,  in 
three  out  of  five  dogs  thus  operated,  response  to  the  interrupted  current  in 
the  facial  nerve  distribution.  Kennedy  (191 1)  has  shown  experimentally  in 
dogs  and  monkeys  that  in  facial  crossing  with  either  the  spinal  accessory  or 
hypoglossal  gave  approximately  the  same  degree  of  motor  return.  Increase  of 
tone  first  appears  with  a  decrease  in  the  asymmetry,  followed  by  return  of  motor 
control  of  the  orbicularis  oculi.  Following  this  regeneration  the  eye  first 
closes  separately  and  not  synchronously  with  the  normal  side.  This  lack 
of  co-ordination  is  subsequently  overcome;  closure  becomes  an  associated 
movement  and  reflex  winking  is  present.  In  hypoglossofacial  crossing  return, 
of  this  movement  is  somewhat  earlier  than  in  the  spinofacial.  In  the  monkey, 
after  spinofacial  crossing,  there  were  spasms  in  most  of  the  facial  muscles  on 
movement  of  the  shoulder,  particularly  when  the  movement  was  sudden. 
Movements  associated  with  tongue  movements  were  generally  wanting  in 
hypoglossofacial  crossing.  However,  in  one  dog,  in  which  end-to-side  suture 
had  been  done,  winking  occurred  with  the  movements  of  the  tongue  and  still 
more  vigorous  movements  of  the  tongue  were  accompanied  by  synchronous 
movements  of  the  face.     Thus,  experimentally,  there  is  little  evidence  favoring 

197 


198         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

one  method  over  the  other.  Both  show  relatively  the  sanae  degree  of  motor 
return,  but  both  show  associated  movements  which  are  more  noticeable  in 
spinofacial  than  hypoglossofacial  crossing.  In  time  of  regeneration  the  differ- 
ence in  favor  of  hypoglossofacial  is  insignificant. 

In  Cushing's  (1903)  case  of  spinofacial  crossing  marked  associated  move- 
ments of  the  facial  musculature  accompanied  turning  of  the  head  or  raising 
of  the  shoulder.  Similar  association  movements  following  spinofacial  suture 
were  found  in  the  cases  of  Harve  (1906),  Girard  (1906),  Davidson  (1907),  Fagge 
(1909)  and  others.  These  associated  movements  were  reported  as  the  only 
evidence  of  return  of  function  by  Ballance  (1903)  and  Gluck  (1905),  while  Ken- 
nedy (1902,1911),  Grant  (1910)  Crandon  (1913),  Hunt  (191 5)  have  reported 
marked  improvement  with  httle  development  of  associated  movements. 
Kennedy's  case  showed  perhaps  the  best  result  "the  movements  taking  place  in 
the  face.  .  .were  quite  independent  of  any  of  the  associated  movements,  were 
made  quite  voluntarily  by  the  patient  in  a  natural  manner.  When  she  was 
asked  to  close  her  eye,  that  was  done  without  any  movement  of  the  muscles 
supplied  by  the  spinal  accessory,  and  on  ordinary  movement  of  the  latter  no 
facial  twitchings  were  observed."  On  the  contrary  in  one  case  under  my 
observation  ten  years  after  spinofacial  end-to-end  crossing,  the  only  movements 
of  the  facial  muscles  were  association  movements,  synchronous  with  turning 
the  head  or  raising  the  shoulder.  The  eye  could  not  be  closed  except  when 
the  shoulder  was  raised  or  the  neck  was  turned.  The  only  real  improvement 
was  in  the  general  tone  of  the  musculature,  with  attendant  decrease  in  the 
asymmetry  of  the  face.  No  emotional  control  had  been  gained.  However, 
by  intensive  electrical  treatment,  repeated  and  constant  attempts  at  re-educa- 
tion intended  to  re-establish  volitional  control,  the  movements  of  the  eye  were 
so  improved  that  the  eye  could  be  closed  without  moving  the  shoulder.  Though 
the  eye  no  longer  participated  in  shoulder  movements,  the  remainder  of  the 
facial  musculature  still  showed  violent  spasmodic  contractions  on  elevation  of 
the,  arm  or  in  other  movements  involving  the  shoulder  and  also  on  rapid 
turning  of  the  head. 

At  first,  hypoglossal  crossing  gave  results  little  better  than  spinofacial 
crossing.  Korte  (1903)  reported  that  voluntary  movements  had  returned 
in  his  cases  in  that  the  orbicularis  oculi  contracted  and  the  angle  of  the  mouth 
could  be  raised.  Bernhardt  (1905)  reporting  on  the  same  cases,  claimed 
that  the  patients  were  unable  to  close  the  eye,  and  the  face  at  rest  showed  no  im- 
provement.    Following  this,  other  similar  cases  were  published,  notably  by 


FACIAL    NERVE 


199 


Ballance,  Ballance  and  Stewart  (1895),  Frazier  and  Spiller  (1903),  Bardenheuer 
(1904),  Taylor  and  Clark  (1906),  Ballance  (1909),  Tubby  (1909),  Welty  (1914), 


STeRNO-f^ASTUlD 
TRAPEZIUS 


Fig.  71. — Schema  to  illustrate  the  cortical  connections  between  the  movements  of  the  face, 
tongue,  and  shoulder,  respectively,  and  the  relations  of  the  corresponding  nerves  in  the  medulla. 
It  will  be  seen  that  the  centers  of  the  movements  of  the  tongue  and  the  face  overlap  in  the  cortex, 
while  that  for  the  shoulder  is  some  distance  away  from  the  face.  It  will  also  be  observed  that  the 
facial  nerve  in  the  medulla  derives  some  of  its  fibers  from  the  hypoglossal  nucleus.  (Ballance, 
Ballance  and  Stewart,  Brit.  Med.  Jour.,  1903.) 


Stevens  (1917),  Bevers  (1913),  Deanesly  (1913)  and  Perret  (1920).  Taylor  and 
Clark  preferre  dimplantation  of  the  facial  into  a  slit  made  in  the  hypoglossal  nerve . 
In  their  seven  cases  there  were  trophic  changes  and  paralysis  of  one  side  of 


200         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

the  tongue,  which  in  the  majority  ultimately  cleared  up,  while  in  all  of  them 
some  return  of  movement  occurred  in  the  facial  musculature.  Improvement 
was  found  first  in  the  general  tone  of  the  muscles,  then  contraction  in  the 
muscles  about  the  mouth,  and  the  improvement  gradually  extended  upward 
to  the  muscles  of  the  forehead.  This  sequence  of  return  of  function  does  not 
always  take  place.  Frequently,  the  movements  of  the  eyelid  return  first  and 
are  followed  by  those  of  the  mouth  and  lastly  of  the  forehead. 

Ballance,  Ballance  and  Stewart  recommend  hypoglossofacial  rather  than 
spinofacial  crossing  because  the  association  between  the  cortical  center  of  the 
tongue  and  face  is  closer  than  that  between  those  for  shoulder  and  facial 
movements.  (See  Fig.  71.)  Frazier  and  Spiller  also  favor  hj^poglossofacial 
for  the  same  reason.  Ballance  reports  a  casein  which  the  end  of  the  facial  was 
sutured  into  the  hypoglossal  and  the  distal  end  of  the  hypoglossal  to  the  spinal 
accessory.  Twenty  months  after  this  double  crossing  the  patient  showed  func- 
tional return  of  the  facial  movements  without  any  associated  tongue  movements. 
However  on  sudden  movements  of  the  shoulder  a  wave  of  contraction  was  seen  to 
pass  from  the  back  of  the  tongue  to  the  tip  on  the  side  of  the  crossing.  Ferret 
reported  a  case  of  hypoglossofacial  crossing  seven  years  after  operation  in  which 
there  was  no  facial  asymmetry  and  little  lagophthalmus,  gradually  improving 
tongue  atrophy  with  perfect  speech.  There  remained  only  a  suggestion  of 
associated  movements  of  the  facial  muscles  with  those  of  the  tongue.  Stevens, 
and  Welty  have  reported  marked  disturbances  in  the  tongue  musculature  with 
decided  speech  impediment  and  difiiculty  in  eating,  so  much  so  that  Welty 
decided  to  discard  this  operation  in  favor  of  the  spinofacial  crossing. 

From  purely  anatomical  considerations,  the  opportunity  for  functional 
restitution  with  closer  associational  correspondence  seems  to  He  more  with 
h;ypoglossofacial  crossing.  These  two  nerves  are  more  or  less  closely  situated 
in  the  brain  stem.  (See  Fig.  72.)  Both  are  richly  supplied  by  collaterals  from 
the  fifth  nerves  of  the  same  and  opposite  sides  (Cajal).  Collaterals  are  also 
given  off  from  the  hypoglossal  to  the  facial.  The  latter  collaterals  have  not 
been  demonstrated  anatomically,  but  their  presence  has  been  deduced  from  the 
fact  that  certain  hypoglossal  nerve  palsies  are  accompanied  by  weakness  of  the 
labiofacial  muscles.  Both  nerves  are  motor:  the  facial,  splanchnic  motor  and  the 
hypoglossal,  somatic  motor.  The  functional  association  of  the  facial  muscles  and 
of  those  of  the  tongue  are  many;  even  from  early  fife  they  are  synergists.  The  act 
of  sucking  is  a  synergic  movement,  as  is  also  chewing,  swallowing,  talking,  and 
other  normal  associated  movements,  hence  in  these  two  nerves  there  is,  even  in 


FACIAL    NERVE 


20I 


-B 


-C 


Fig.  72. — Schematic  drawing  of  tlie  brain  stem  sliowing  the  connections  between  the  trigeminal; 
facial,  h>'poglossal  and  spinal  accessory  nerves.  Horizontal  section.  ///,  Oculomotor  nucleus, 
IV,  trochlear  nucleus;  V,  spinal  trigeminal  sensory  nucleus;  VI,  abducens  nucleus;  VII,  facial 
nucleus;  XII,  hypoglossal  nucleus;  XI,  spinal  nucleus  of  the  spinal  accessory;  a,  collaterals  from  the 
spinal  trigeminal  to  the  facial  and  hj-poglossal  nuclei  of  the  same  side;  a',  collaterals  to  the  facial 
and  hypoglossal  nuclei  from  fibers  passing  from  the  spinal  trigeminal  nucleus  to  the  opposite  side; 
a",  collaterals  to  the  facial  and  hypoglossal  nuclei  arising  from  the  spinal  trigeminal  nucleus  of  the 
opposite  side;  B  and  C,  aberrant  pyramidal  fibers;  B,  occulocephalogyric  bundle  to  ///.  71',  1'/  and 
XI  nerves;  C,  mandibulofacial  bundle  to  V,  VII ,  and  XII  nerves. 


202 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


the  lower  centers,  a  close  correspondence  in  reflex  function  as  well  as  in  ana- 
tomical relationship.  Whereas  on  the  contrary,  the  nuclei  of  the  spinal  portion 
of  the  spinal  accessory  nerve  are  placed  farther  away  from  the  facial,  and  receive 
no  reflex  collaterals  from  the  trigeminal.  These  collaterals  probably  play  an 
important  part  in   the  re-establishment  of  reflex  facial  movements,  since  it  is 


Fig.  73. — Section  to  show  collaterals  ending  in  the  hypoglossal  nucleus.  Portion  of  a  transverse 
section  of  the  medulla  of  a  mouse  at  the  level  of  the  commissural  nucleus.  Chrome-silver  impregna- 
tion of  Golgi.  .-1,  Commissural  nucleus  B,  hypoglossal  nucleus  C.  decussating  fibers  of  the  medial 
lemniscus;  D.  sohtary  fasciculus  cut  transversely,  E,  secondary  trigeminal  and  vago-glossopharyn- 
geal  tracts;  /.  g,  /,  collaterals  from  the  secondary  trigeminal  and  glossopharyngeal  tracts  termin- 
ating in  the  nucleus  of  the  hypoglossal.     (Cajal,  Hist,  du  Systeme  Nerveuse.) 

possible  that  the  trigeminal  fibers  carry  (see  Figs.  73  and  74)  muscle  and  position 
sense  for  the  facial  muscles.  It  is  true  that  the  exact  path  of  these  stimuli  has 
not  yet  been  determined,  but  the  facial  muscles,  are  so  intimately  connected 
with  the  skin  that  it  is  probable  that  the  sensation  of  skin  movements  in 
the  face  serve  as  proprioceptive  stimuli,  and  are  carried  by  the  trigeminal  nerve. 
This  proprioceptive  sense  in  the  facial  musculature  seems  to  be  lost  when  the 


FACIAL    NERVE 


203 


posterior  root  of  the  trigeminal  nerve  is  cut.     These  patients  find  it  difficult  to 
localize  the  exact  position  of  the  cheek,  and  the  face  feels  "wooden." 

The  cranial  or  accessory  portion  of  the  spinal  accessory  nerve  belongs  in 


Fig.  74.' — Section  to  show  collaterals  ending  in  the  facial  nucleus.  Portion  of  a  transverse 
section  of  the  medulla  of  a  mouse  several  days  old,  at  the  level  of  the  nucleus  of  the  facial  nerve. 
Chrome-silver  impregnation  of  Golgi.  C,  Nucleus  of  the  facial  nerve  which  is  shown  receiving 
collaterals,  d.  from  the  secondary  trigeminal  fibers  passing  transversely  through  the  reticular  forma- 
tion; a,  b,  collaterals  from  the  continuation  of  the  lateral  column;  A ,  afferent  root  of  the  glossopharyn- 
geus;  B,  spinal  root  of  the  trigeminus,  cut  transversely.  Collaterals  whose  fibers  are  shown  passing 
inward  forming  a  plexus,  E,  which  ends  in  the  terminal  nucleus  of  the  trigeminus.  (Cajal,  Hist,  du 
Systeme  Nerveuse.) 


reality  to  the  vagus,  and  immediately  after  its  exit  from  the  cranial  cavity  it 
joins  the  vagus  and  is  distributed  through  the  vagus  to  the  laryngeal  muscles. 
Consequently,  only  the  spinal  portion  of  the  spinal  accessory,  whose  cells  of 


204         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

origin  lie  in  the  ventral  column  of  the  upper  five  or  six  cervical  segments 
and  not  in  the  medulla,  can  be  used  in  spinofacial  crossing.  The  spinal  acces- 
sory nerve  is  splanchnic  motor,  and  its  nucleus  lies  in  the  lateral  portion  of  the 
ventral  gray,  forming  the  lower  part  of  an  almost  continuous  column  of  motor 
cells  which  includes  the  splanchnic  motor  nuclei  of  origin  of  the  seventh, 
ninth  and  tenth  nerves;  all  supply  structures  originally  of  splanchnic  origin. 
The  facial  muscles  and  the  trapezius  are  both  splanchnic  in  origin,  that  is, 
derived  from  the  lateral  and  not  the  dorsal  mesoderm.  The  trapezius  is 
splanchnic  and  may  be  considered  homologous  with  certain  muscles  moving 
the  pectoral  arch.  It  is  held  that  one  or  more  branchial  arches  are  retained  for 
the  attachment  of  the  forelimb  and  the  muscles  which  move  this  arch  have  been 
preserved  in  the  trapezius  (Johnson,  1906).  The  facial  muscles  develop  from 
the  hyoid  arch. 

In  spite  of  this  developmental  homology,  the  reflex  paths  of  association  of 
the  facial  and  spinal  accessory  nerves  are  quite  independent,  unconnected,  and 
widely  separated.  The  muscles  of  the  shoulder  and  face  are  not  synergists  and 
have  little  or  no  association  in  function.  Not  only  in  the  brain  stem  but  in  the 
cortex  there  is  still  less  connection  between  the  centers  for  shoulder  and  face 
movements  (see  Fig.  71),  as  has  been  shown  by  Ballance,  Ballance  and  Stewart, 
and  Frazier  and  Spiller.  The  face  and  tongue  centers  lie  closer  together  and  con- 
sequently association  paths  may  be  more  readily  established,  so  that  in  hypo- 
glossofacial  crossing  new  associated  movements  should  be  more  easily  developed 
and  volitional  control  more  easily  gained. 

It  remains  a  mooted  question  of  nerve  physiology  whether  the  cortical 
facial  center  (after  severance  of  the  facial  nerve  and  nerve  crossing)  remains 
inactive,  while  the^tongue  center  or  the  shoulder  center,  as  the  case  may  be, 
takes  on  the  function  of  the  facial.  From  the  experimental  work  of  Kennedy 
and  others,  where  nerves  were  crossed,  for  example,  the  nerve  to  flexors  into 
that  of  extensors  in  the  dog,  it  was  found  that  the  fle.xors  and  extensors  had 
interchanged  their  function,  so  that  stimulation  of  the  cortical  flexor  center 
resulted  in  extensor  contraction,  and  vice  versa.  In  order  that  there  can  be 
volitional  associated  movements  following  nerve  crossing,  facial  proprioceptive 
impulses  must  be  transmitted  in  some  manner  to  the  new  functioning  cortical 
facial  center,  so  as  to  regulate  the  movement  of  the  facial  muscles. 

From  these  anatomical  and  physiological  considerations,  the  hypoglossal 
nerve  offers  greater  possibiHties  for  facial  crossing.  The  paralysis  resulting 
from  section  of  the  substituted  nerve  must  always  be  considered.     If  complete 


FACIAL    NERVE  205 

end-to-end  suture  is  done  the  marked  hemiatrophy  of  the  tongue  resulting 
from  complete  severance  of  the  hypoglossal  is  a  serious  drawback  to  the  utiliza- 
tion of  this  nerve,  unless  another  motor  nerve  is  sutured  into  the  cut  distal 
stump.  In  unrepaired  total  section  of  the  hypoglossal  one-half  the  tongue 
becomes  little  more  than  a  layer  of  mucous  membrane.  This  disability  Welty 
considered  serious,  while  Ballance,  Ballance  and  Stewart,  Frazier  and  Spiller 
do  not  believe  this  atrophy  of  serious  importance,  and  the  latter  consider  the 
paralysis  resulting  from  section  of  both  the  spinal  accessory  and  the  hypo- 
glossal equally  insignificant.  Certainly  the  paralysis  resulting  from  total 
section  of  the  spinal  accessory  is  not  very  disabling,  but  it  is  sufifiicient  to  cause 
some  disability  in  the  free  and  forcible  movements  in  elevation  of  the  arm  and 
shoulder.  These  points  must  be  weighed  in  their  relation  to  the  occupation 
and  station  of  the  individual.  In  a  singer  the  spinal  accessory  should  be  used 
for  crossing.  A  hod  carrier  could  better  sacrifice  his  hypoglossal.  The  advan- 
tages of  complete  end-to-end  suture  over  partial  crossing  or  implantation  are 
that  dissociation  is  better  established  and  a  more  proportionate  number  of 
neuraxes  offered  by  the  substitution.  Complete  section  of  the  substitute  nerve 
allows  complete  severance  of  the  centers  from  their  former  function  and  all  the 
neurons  will  be  called  upon  to  serve  only  the  new  and  not  both  the  new  and  old 
simultaneously. 

Taylor  has  shown  good  results  from  implantation.  Yet  I  do  not  think 
that  this  type  of  operation  aft'ords  the  best  opportunities  for  recovery.  Bal- 
lance strongly  advises  against  any  method  which  does  not  devote  the  whole 
nerve  for  suture,  condemning  end-to-side  suture  or  an  end-to-end,  where  only 
part  of  either  the  spinal  accessory  or  the  hypoglossal  nerves  is  used.  If  the 
hypoglossal  nerve  be  used  and  the  descendens  hypoglossi  separated  from 
the  main  nerve  trunk,  the  latter  may  be  sutured  into  the  distal  end  of  the  hypo- 
glossal and  atrophy  of  the  tongue  thus  overcome,  providing  regeneration  takes 
place.  Although  the  descendens  hypoglossi  is  sutured  to  the  distal  end, 
nevertheless  the  hypoglossal  nerve  is  freed  from  its  former  central  connections, 
since  the  descendens  hypoglossi  consists  of  motor  libers  from  the  first  and 
second  cervical  nerves  only,  which  have  become  incorporated  in  the  sheath  of  the 
hypoglossal  in  the  early  development  of  the  embryo.  Thus  a  nerve  whose  fibers 
are  distinct  from  the  hypoglossal  is  used  to  offer  new  motor  neurons  for  the 
tongue. 

In  the  formation  of  the  cervical  flexure  the  formerly  independent  horizontal 
buds  of  the  hypoglossal  and  the  first  and  second  cervical  nerves  come  in  con- 


2o6         SURGICAL   AND    MECHANICAL   TREATMENT    OF   PERIPHERAL   NERVES 


tact.     (See  Figs.  75,  76,  77,  78.)     The  latter  are  temporarily  incorporated  in 
the  trunk  of  the  hypoglossal  by  the  growth  of  the  sheath  and  separate  later 

Hypo^lossa-L  N. 


Descendens  Kypo^lossi-  N 


HypodloS5j»l   N 


DescencJens    hypodlossL  N, 


Fig.  75. 


Fig.  76 


HypoglobSi-l  N. 

Descendens   hypo^lossL  N. 


HypogLoisa^L  N. 


Descendens  hypoglossL  N 


Fig.  77.  Fig.  78. 

Figs.  75,  76,  77,  78. — Schematic  drawing  showing  the  development  of  the  hypoglossal  and  the 
descendens  hypoglossi  nerves.  The  nerves  arise  as  separate  rootlets  from  the  lower  part  of  the 
medulla  and  the  adjacent  segments  of  the  cervical  cord.  With  the  formation  of  the  cervical  flexure 
the  two  nerves  come  to  lie  in  contact  for  a  short  distance  before  again  separating,  but  the  fibers  do 
not  intermingle. 

from  the  sheath  as  the  descendens  hypoglossi.  From  a  comparative  anatomy 
standpoint  the  hypoglossal  nerve  itself  represents  the  most  cephalic  portion  of 
the  cervical  ple.xus  supplying  muscles  between  the  pectoral  girdle  and  the 
region  of  the  tongue.     In  the  higher  vertebrates  this  most  cephalic  portion  of 


FACIAL   NERVE  207 

the  cervical  plexus,  supplying  the  muscles  of  the  tongue,  has  gradually  become 
independent,  and  thus  has  formed  the  hypoglossal  nerve.  By  suturing  the 
descendens  hypoglossi  into  the  distal  end  of  the  hypoglossal,  neuraxes  which 
come  from  the  first  and  second  cervical  segments,  but  phylogenetically  and 
physiologically  closely  related  to  the  tongue  musculature  innervation,  are 
utilized.  Thus  the  contour  of  the  tongue  may  be  restored  and  its  tone 
maintained. 

Grant  (1910)  has  lessened  the  disability  resulting  from  total  section  of  the 
spinal  accessory  nerve  by  suturing  to  its  distal  end  a  motor  nerve  from  the 
cervical  plexus  or  the  descendens  hypoglossi  and  in  this  manner  offers  motor 
innervation  to  the  trapezius  muscle.  A  similar  method  has  been  employed 
by  Ballance;  the  spinal  accessory  was  sutured  into  the  distal  end  of  the  hypo- 
glossal, thus  restoring  the  muscle  volume  of  the  tongue,  though  on  movements 
of  the  shoulder,  a  slight  contraction  wave  in  the  tongue  beginning  at  the  base 
and  passing  toward  the  tip  took  place.  In  place  of  the  spinal  accessory  the 
descendens  hypoglossi,  as  has  been  indicated,  may  be  freed  from  the  main  nerve 
trunk,  and  sutured  into  the  distal  end  of  the  hypoglossal.  Since  paralysis 
resulting  from  severance  of  the  descendens  hypoglossi  is  barely  appreciable,  the 
advantages  of  this  nerve  as  a  substitute  for  either  the  spinal  accessory  or 
hypoglossal  are  apparent. 

Sherren  (1906)  collected  fifty  cases  of  facial  nerve  suture  of  which  eight 
were  complete  and  two  were  partial  crossing.  In  six  patients  the  hypoglossal 
was  used  and  in  the  other  the  spinal  accessory.  Only  two  of  these  were  fol- 
lowed longer  than  six  months  after  operation,  so  that  only  these  admit  of  any 
conclusions  of  value  being  drawn.  Of  the  two  patients  observed  six  months,  one 
was  spinofacial  and  the  other  hypoglossofacial  and  in  both  associated  move- 
ments were  present.  Some  of  the  remaining  operations  were  implantations  and 
the  others  were  partial  crossings.  In  quite  a  few  of  the  implantations  a  slit  was 
made  deeply  into  the  hypoglossal  nerve;  in  effect  possibly  partial  nerve  crossing. 
Paralysis  of  the  tongue,  either  permanent  or  of  several  months  duration, 
resulted,  thus  indicating  that  the  funiculi  were  probably  actually  cut  and  not 
merely  separated  as  is  done  when  a  true  implantation  is  made.  Even  when  a 
flap  consisting  of  one-third  or  one-half  the  cross  area  of  the  hypoglossal  nerve  is 
raised,  as  in  partial  nerve  crossing,  only  temporary  paralysis,  as  Sherren  has 
pointed  out,  may  result.  All  cases  of  nerve  crossing  showed  some  improvement 
in  the  symmetry  of  the  face.  In  a  few  of  the  spinofacial  cases  some  dissociation 
from    the  shoulder    movements  with   a   slight   amount   of  volitional   control 


2o8         SURGICAL   AXD    MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 

occurred,  whereas  in  h3rpoglossofacial  the  movements,  especially  those  of  the 
angle  of  the  mouth,  showed  dissociation,  but  the  amount  of  voUtional  control 
in  the  latter  was  greater. 

Operative  Indications. — The  indications  for  surgical  repair  of  the  facial 
nerve  depend  on  the  nature  of  the  injury.  If  the  nerve  has  been  severed  by 
trauma,  as  from  stab  or  gunshot  wounds  or  during  an  operation  upon  a  mastoid, 
the  indications  for  suture  are  plain.  In  fractures  of  the  base  the  nerve  may 
be  torn  within  the  cranial  cavity.  Very  rarely,  both  facial  nerves  may  be 
injured,  but  such  traumatic  bilateral  paralysis  is  extremely  rare  in  civilian 
life,  only  a  few  cases  having  been  reported,  notably  those  of  Koslossky  (1892) 
and  Ransohoff  (1919).  When  the  injury  is  bilateral,  some  form  of  repair  is 
imperative  for  the  deformity  is  distressing,  not  only  in  appearance  but  in 
attempts  to  articulate  and  to  eat.  Moure  (1915)  and  Brindel  (1917)  have 
shown  that  in  fractures  and  gunshot  wounds  facial  paralysis  may  be  caused 
by  pressure  of  bony  fragments,  and  that  function  may  be  re-established  by 
removal  of  the  fragments  and  cleaning  up  the  facial  canal — in  short  by  nerve 
liberation. 

When  the  paralysis  is  the  result  of  otitis  media,  one  should  wait  at  least 
six  months  to  allow  spontaneous  regeneration  to  occur,  and  during  this  time  the 
facial  muscles  should  be  supported  mechanically  to  prevent  overstretching  and 
massage  and  electricity  should  be  given  daily.  During  tliis  interval  the  mastoid 
should  be  cleaned  out,  getting  rid  of  any  residual  infection,  granulation  tissue, 
organized  exudation  or  any  source  of  pressure  which  might  interfere  with  nerve 
conductivity.  Excellent  results  have  been  reported  from  this  form  of  treat- 
ment by  Galdiz  (1911),  Catte  and  Sigaux  (1912)  and  others.  However, 
if  such  treatment  is  not  followed  by  some  return  of  function  within  six 
months  little  may  be  expected  by  way  of  regeneration  without  nerve 
suture.  When  paralysis  develops  some  time  after  a  radical  mastoid  opera- 
tion, it  is  reasonable  to  infer  that  interference  in  conductivity  is  due  to  pres- 
sure upon  the  nerve  or  to  persistent  perineural  inflammation  and  a  second 
operation  on  the  mastoid  may  be  undertaken  in  the  hope  of  removing  any 
disease  which  may  remain. 

In  Bell's  palsy  and  more  particularly  in  paralysis  occurring  in  infants  and 
children,  a  few  facial  nerve  fibers  may  be  spared,  sufficient  to  maintain  the 
vasomotor  status  and  a  certain  degree  of  tone,  or  with  even  as  light  innervation 
in  some  of  the  muscles,  especially  those  about  the  mouth.  There  is  some 
ground  for  the  suggestion  that  retention  of  tone  in  the  facial  muscles  in  some 


FACIAL    NERVE  209 

forms  of  facial  paralysis  may  be  due  to  the  integrity  of  the  non-meduUated 
efferent  sympathetic  fiber  for  it  is  well  known  that  striate  musculature  possess 
a  dual  innervation  receiving  efferent  fibers  from  the  sympathetic  as  well  as  the 
ventral  gray  cells.  Evidence  of  the  integrity  of  some  of  the  nerve  fibers  in 
these  cases  is  seen  immediately  after  section  and  suture  when  the  deformity 
becomes  more  marked  due  to  severance  of  the  intact  fibers.  These  fibers 
possibly  prevent  marked  regressive  changes  in  the  muscles;  consequently  nerve 
crossing  may  be  done  at  a  late  period — many  years  after  the  original  paralysis — 
with  excellent  functional  return  in  the  facial  musculature.  But  when  enough 
fibers  exist  to  maintain  the  tone  and  prevent  very  much  asymmetry  of  the  face, 
the  surgeon  should  be  most  hesitant  in  suggesting  operation  without  first  having 
relaxed  the  muscles  by  proper  support  for  at  least  six  months  to  allow  for 
spontaneous  regeneration. 

Attention  has  been  called  to  the  greater  frequency  of  Bell's  palsy  on  the 
right  than  on  the  left  side.  Leiner  (1919)  found  that  in  twenty-six  cases  of 
Bell's  palsy  the  paralysis  was  on  the  right  in  nineteen  and  on  the  left  in  seven. 
He  believes  that  the  greater  frequency  on  the  right  side  is  due  to  the  fact  that 
the  facial  canal  and  stylomastoid  foramen  is  smaller  on  the  right  than  on  the 
left.  In  thirty-three  skulls  examined  by  him,  the  right  stylomastoid  foramen 
was  smaller  than  the  left  in  nineteen  instances  and  equal  to  the  left  in  five, 
while  in  nine  the  right  was  larger  than  the  left.  Philip  has  called  attention  to 
the  fact  that  in  some  skulls  the  stylomastoid  foramen  is  reduced  to  the  size  of 
a  minute  thread. 

When  the  facial  canal  or  stylomastoid  foramen  is  abnormally  small,  it  is 
extremely  difficult,  if  not  impossible,  to  find  the  facial  nerve  as  it  may  be 
reduced  to  a  mere  thread,  while  in  agenesis  of  the  facial  nucleus  the  nerve  fails 
to  develop  and  consequently  is  not  to  be  found. 

The  facial  nerve  may  be  injured  during  childbirth  due  to  the  pressure  of 
forceps,  often  causing  a  bilateral  injury.  Congenital  maldevelopment  of  the 
facial  nucleus  and  nerve  is  also  met  with  but  is  usually  associated  with  develop- 
mental disturbances  in  the  sixth  nerve  or  other  congenital  anomalies  such  as 
spina  bifida,  mental  defects,  etc. 

Before  operating  on  facial  paralyses,  other  than  those  in  which  it  is  certain 
that  the  nerve  has  been  severed,  every  opportunity  should  be  given  to  allow 
spontaneous  regeneration  to  take  place.  Such  delay  is  especially,  indicated 
since  end-to-end  repair  of  the  facial  nerve  is  rarely  possible  and  instead,  some 
form  of  nerve  crossing  must  be  done.     The  operation  of  choice  is  obviously 


2IO         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

end-to-end  suture — uniting  the  central  end  of  the  facial  with  the  distal.  This 
is  possible  in  comparatively  few  cases.  In  others  when  both  the  central  and 
distal  ends  can  be  identified  and  yet  not  brought  in  apposition  a  single  nerve 
graft  may  be  done,  using  a  segment  of  one  of  the  cutaneous  nerves  such  as  the 
radial  or  short  saphenous.  By  careful  suture  and  accurate  apposition  a  single 
graft  can  be  made  to  cover  the  entire  cross  area,  thus  insuring  better  down- 
growth  than  when  a  cable  graft  is  used  such  as  is  required  in  larger  nerves. 
Due  to  the  anatomical  arrangement  of  the  facial  canal  there  is  little  opportunity 
for  unaided  regeneration  if  scar  and  callus  are  present.  Because  of  the  rigid 
walls  of  the  canal  and  the  fact  that  the  diameters  of  the  canal  and  the  nerve 
are  nearly  equal  the  smallest  amount  of  scar  or  exudate  is  effective  in  blocking 
nerve  regeneration  or  in  causing  sufficient  pressure  to  produce  interruption 
of  nerve  conductivity. 

OPERATIVE  TECHNIC 

Incision. — The  incision  to  expose  the  facial  nerve  is  made,  beginning  at  the 
ventral  margin  of  the  mastoid  about  3  cm.  above  the  tip.  It  is  carried 
directly  downward  for  6  to  8  cm.  and  then  curved  slightly  forward  in  the 
fold  of  the  skin  usually  found  at  this  le\el.  The  posterior  occipital  vein  is 
generally  encountered  just  before  it  joins  the  temporal  to  form  the  external 
jugular.  It  is  best  to  ligate  the  vein  both  proximally  and  distally  and  to  cut 
between,  since  it  usually  crosses  the  wound  and  is  in  the  way. 

Exposure  of  the  Facial  Nerve. — The  deep  fascia  is  cut  in  the  same  line  as 
the  superficial  incision,  care  being  taken  to  avoid  opening  the  sheath  of  the 
parotid  gland.  The  gland  is  freed  by  blunt  dissection  beginning  dorsally  and 
working  forward,  and  retracted  ventrally  by  a  blunt  hook.  (See  Fig.  79.)  The 
tip  of  the  mastoid  ventrally  may  be  chiselled  oft"  together  with  the  muscular 
attachments  of  the  sternocleidomastoid  muscle  if  there  is  much  scar  and  the 
nerve  difficult  to  find,  thus  permitting  easier  access  to  the  facial  nerve  at  its 
exit  just  behind  the  styloid  process.  Unless  the  facial  is  difficult  to  find  the 
mastoid  is  let  alone.  The  digastric  muscle  is  retracted  down  and  backward; 
but  should  the  muscle  be  unusually  large  and  well  developed  a  part  of  the 
muscle  belly  must  be  cut  transversely  so  as  to  permit  exposure  of  the  nerve. 
Along  the  upper  border  of  this  muscle  the  posterior  auricular  artery  will  be 
found  and  should  be  ligated  in  order  to  secure  a  clear  field.  Generally  the 
finger  can  identify  the  nerve  at  a  depth  of  about  2  cm.,  or  a  blunt  hook  may 
be  inserted  in  the  stylomastoid  foramen  and  the  nerve  picked  up  as  it  makes  its 


FACIAL   NERVE 


211 


exit.     If  the  paralysis  is  not  complete,  however,  a  small  unipolar  electrode  will 
be  found  most  valuable.     The  nerve  should  be  exposed  as  high  as  possible. 

With  the  nerve  still  intact  two  fine  silk  sutures  are  passed  just  distal  to 
the  point  at  which  the  nerve  is  to  be  cut.  These  sutures  should  be  placed  equi- 
distantlv  and  the  needles  left  on  the  sutures.     The  nerve  is  then  cut   clean 


T^;.e.L  W, 


RxroUa^Ut- 


E,\{.C6.r'i.lAA.~~ 
IntJ-u^.Y 


Fig.  79. — Spinofacial  nerve  crossing.     Exposure  of  the  facial  nerve. 


across  with  a  fine,  thin  blade.  Sutures  can  be  passed  with  greater  ease  before 
the  nerve  is  cut — an  important  point  to  remember.  The  nerve  and  sutures 
are  then  covered  with  moist  cotton  to  protect  the  nerve  until  the  rest  of  the 
lield  is  exposed.  If  the  dissection  has  been  properly  done,  2}4  to  3  cm.  of  the 
facial  nerve  may  be  exposed.  After  a  mastoid  operation  with  much  scar 
tissue  the  exposure  is  more  difficult  and  here  it  is  best  to  cut  off  a  little  of 
the  bone,  making  a  subperiosteal  dissection  down  to  the  nerve. 


212 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Exposure  of  the  Spinal  Accessory  Nerve. — The  spinal  accessory  nerve 
passes  dorsal  to  the  facial  nerve  either  in  front  or  behind  the  internal  jugular 
vein  at  the  level  of  the  transverse  process  of  the  atlas.  The  occipital  artery 
will  be  met  with  running  along  the  lower  border  of  the  digastric  muscle.  It 
should  be  identified  and  ligated.     The  transverse  process  of  the  atlas  can  readily 


Fig.  8o. — Spinofacial  nerve  crossing.     Exposure  of  the  spinal  accessory  nerve. 

be  felt  and  the  nerve  identified  upon  it  lying  beneath  a  layer  of  deep  fascia  which 
encloses  both  the  transverse  process  and  the  internal  jugular  vein  and  must 
be  cut  in  order  to  expose  the  nerve.  During  this  part  of  the  operation  the 
digastric  muscle  is  retracted  upward  and  the  sternocleidomastoid  muscle  down- 
ward and  out,  exposing  its  medial  or  deep  surface  across  which  the  spinal  acces- 
sory nerve  traverses  the  muscle  at  about  the  junction  of  the  upper  and  middle 
thirds.  (See  Fig.  80.)  The  nerve  may  be  identified  in  the  wound  by  a  unipolar 
electrode  or  by  pinching  and  watching  for  elevation  of  the  shoulder. 


FACIAL    NERVE  213 

Lying  in  front  of  the  internal  jugular  and  the  transverse  process  of  the 
atlas,  between  the  internal  jugular  and  internal  carotid,  the  hypoglossal  and 
vagus  nerves  may  be  felt.  The  carotid  sheath  is  split  to  expose  the  hypoglossal 
nerve  at  about  the  level  of  the  occipital  artery  where  it  crosses  the  carotid. 
Running  along  the  outer  border  of  the  hypoglossal  nerve  is  the  descendens 
hypoglossi.  The  descendens  hypoglossi  is  dissected  upward,  free  from  its 
inclusion  within  the  sheath  of  the  hypoglossal  and  cut  as  low  as  possible.  The 
central  end  of  the  descendens  hypoglossi  is  then  covered  with  a  small  cotton 
pad  and  isolated  from  the  rest  of  the  field. 

The  spinal  accessory  nerve  is  then  freed  and  the  point  at  which  section 
is  to  be  done  determined.  The  nerve  should  be  cut  low  enough  to  permit 
suture  with  the  facial  nerve  without  tension.  The  sutures  which  have  already 
been  passed  through  the  facial  are  now  carried  through  the  spinal  accessory  be- 
fore the  nerve  is  cut  just  above  the  point  chosen  for  section.  The  sutures  are 
then  held  out  of  the  way  and  the  spinal  accessory  nerve  is  cut.  The  central  end 
of  the  spinal  accessory  is  then  drawn  over  a  small  neatly  folded  cotton  pad 
placed  over  the  lower  border  of  the  digastric  muscle.  The  pad  tends  to  hold  the 
nerve  in  place  during  suture  and  prevents  slipping  thus  avoiding  frequent 
manii)ulation  of  the  nerve. 

The  sutures  are  now  tied,  using  anatomical  forceps.  If  the  sutures  have 
been  accurately  placed,  and  the  proper  amount  of  tension  employed  in  tying, 
accurate  apposition  of  the  nerve  ends  is  obtained.  Unless  the  sutures  are  tied 
with  forceps  this  cannot  be  accomplished  with  the  same  degree  of  accuracy. 
The  descendens  hypoglossi  is  now  sutured  into  the  distal  end  of  the  spinal 
accessory  nerve.     (See  Fig.  8i.) 

No  protection  is  necessary  for  the  suture  line.  Cargile  membrane  need 
not  be  used  unless  there  is  scar  tissue.  Ordinary  cargile  as  has  been  indicated 
is  absorbed  in  two  or  three  weeks  and  is,  therefore,  of  little  value.  If  prolonged 
protection  is  desired  Huber's  alcoholized  cargile  membrane  should  be  used. 
The  wound  should  be  dry  and  closed  in  two  layers  and  the  neck  immobilized 
for  two  weeks.     For  this  purpose  a  Thomas  collar  may  be  used. 

Hypoglossofacial  Suture. — The  same  incision,  exposure  and  preparation  of 
the  facial  nerve  is  done  as  for  the  spinofacial  suture  with  the  exception  that  the 
incision  is  carried  somewhat  farther  forward  in  the  fold  of  the  neck. 

Exposure  of  the  Hypoglossal  Nerve. — The  digastric  muscle  is  pulled 
upward  and  the  sternocleidomastoid  outward.  The  occipital  artery  is  identi- 
fied, ligated  and  cut.     The  sheath  of  the  carotid  is  opened  at  the  lower  angle 


214         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHER.\L    NERVES 

of  the  wound  and  the  hypoglossal  nerve  identified  as  it  crosses  over  the  external 
carotid  artery  and  below  the  occipital.  The  nerve  may  be  identified  by  an 
electrode  or  by  pinching.  The  vagus  may  be  distinguished  by  its  position  farther 
dorsal  and  its  course  directly  downward  behind  the  carotid.     The  hypoglossal 


Fig.  8i. — Spinofacial  nerve  crossing.  The  central  end  of  the  spinal  accessory  has  been  sutured 
to  the  distal  end  of  the  facial.  The  descendens  h^-poglossi  has  been  separated  from  the  hypo- 
glossal, cut  and  its  central  end  sutured  to  the  distal  end  of  the  spinal  accessory.  The  insert  shows 
the  relation  of  the  nerves  after  the  suture. 


nerve  curves  slightly  forward,  its  convexity  downward,  across  the  internal  and 
external  carotid  arteries.  The  hypoglossal  nerve  is  then  exposed  farther  for- 
ward and  the  descendens  hypoglossi  farther  downward  nearly  to  its  union  with 
the  descendens  cervicis.  The  descendens  hypoglossi  is  separated  from  the 
hypoglossal  nerve  by  careful,  sharp  dissection,  along  a  line  of  separation  which 
can  usually  be  made  out.     Dissection  of  both  the  hypoglossal  and  descendens 


FACIAL    NERVE 


215 


hypoglossi  is  carried  high  so  as  to  free  as  much  of  the  nerve  as  possible  and  avoid 
any  angulation  or  kinking  in  the  nerve  after  suture. 

After  the  hypoglossal  nerve  has  been  carefully  exposed  four  sutures  of  fine 
silk  are  passed;  two  on  either  side  immediately  above  and  below  the  level  at 
which  the  nerve  is  to  be  severed.     The  threads  are  left  long  and  the  needles 


Sutured  io  di^'si&L  end  \ 
jC  hypo6lo5ba.L. 


■j^/f^^rr^'-^ 


Fig.  .Sj. — Hypoglos-sofacial  nerve  crossing.  The  central  end  of  the  liypoglossal  nerve  is  sutured 
to  the  distal  end  of  the  facial.  The  descendens  hypoglossi  has  been  separated  from  the  hypoglossal, 
cut  and  its  central  end  sutured  to  the  distal  end  of  the  hypoglossal. 


attached.  The  sutures  have  been  placed  so  as  to  allow  a  margin  and  the 
hypoglossal  nerve  is  then  cut  between  them.  The  central  stump  of  the  hypo- 
glossal is  then  carried  over  or  beneath  the  digastric  and  sutured  to  the  facial 
in  llic  same  manner  as  in  spinofacial  suture.     (See  Fig.  82.) 

The  descendens  hypoglossi  is  then  sutured  to  the  distal  end  of  the  hypo- 


2l6 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


glossal  in  like  manner,  using  the  sutures  previously  passed  in  the  distal  end  of 
the  hypoglossal. 


MECHANICAL  TREATMENT 


In  facial  nerve  paralysis  the  paralyzed  facial  muscles  should  be  supported 
mechanically  and  overstretching  prevented  the  same  as  in  any  other  nerve 
injury.  Support  of  the  facial  muscles  constitutes  a  very  important  part  of  the 
treatment  and  should  be  given  both  before  and  after  operation. 


Fig.  83. — Appliance  to  prevent  overstretching  of  facial  muscles  in  facial  paralysis.  Two  strips 
of  adhesive  connected  with  a  spring  metal  head  piece  by  a  rubber  band.  The  adhesive  is  attached 
to  a  small  leather  piece  having  a  metal  button.  The  rubber  band  connects  this  with  a  similar  button 
on  the  head  piece  thus  giving  an  elastic  support  for  the  facial  muscles. 

Jaeger  (1918)  has  reported  re-establishment  of  function  of  the  facial 
muscles  following  mechanical  treatment  alone  when  a  year  of  electricity  and 
massage  hadjfailed  to  show  any  improvement.  IMechanical  support  has  also 
been  used  by  Elsberg,  Frazier  and  others.  Some  form  of  adhesive  strapping 
is  usually  employed,  the  strapping  being  fastened  to  a  fixed  point  in  the  tem- 
poral region.  The  author  prefers,  in  place  of  a  fi.xed  apparatus,  an  elastic 
support.  A  small  band  may  be  worn  around  the  head  or  a  spring  steel  metal 
over  the  head  similar  to  that  worm  by  telephone  operators.  (See  Fig.  83.) 
Two  straps  of  adhesive  or  transparent  sticking  plaster  may  be  fastened  to  the 
skin  over  the  infra-orbital  and  infrabuccal  muscle  groups  and  then  fastened  to 
a  small  metal  hook.     This  hook  is  then  connected  to  the  head  piece  by  means 


FACIAL    NERVE  217 

of  a  rubber  band  thus  giving  an  elastic  support  which  prevents  overstretching 
and  yet  permits  free  movement  of  the  face. 

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divided  hypoglossal  nerve.  Lancet,  v.  i:  1909,  p.  1675. 
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(pes  anserinus)  des  linken  Nervus  facialis  wegen  einer  16  Jahre  alten  totalen  Lahmung 

des  ganzen  Facialis,  ]Miinchen.  nied.  Wchnschr.,  v.  51:  July  12,  1904,  p.  1273. 
Beck,  J.  C:  Facial  hypoglossal  anastomosis.  Laryngoscope,  v.  17:   1907,  p.  83. 
Beckman,  E.  H.:  The  surgical  treatment  of  facial  paralysis,  J.  Mich.  M.  S.,  v.  13:   1914, 

p.  681. 
Bernhardt,  M.:  Uber    die    sogen.    recidivirenden    Facialislahmung,  Neurol.    Centralbl, 

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gischem  Standpunkte,  Milt.  a.  d.  Grenzgeb.  d.  Med.  u.  Chir.,  v.  16:   1906,  p.  476. 
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Nervenfasern,  MuUer's  .^rchiv.   1842,  p.  102. 
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de  Bordeaux,  v.  47:  1917,  p.  87. 
Chutro,  p.:  Anastomose  spino  faciale,  Bull,  et  mem.  Soc.  de  chir.  de  Par.,  new  ser.,  v.  43: 

1917,  p.  1236. 
CoTTE,G.     and  Sigaux,  G.:  Remarques  sur  la  paralysie  faciale  d'origine  otique  et  son 

traitement  par  I'anastomose  hypoglossofaciale,  Lyon  chir.,  v.  8:   1912,  p.  601. 
Crandon,  L.  R.  G.:  Traumatic  facial  paralysis,  anastomosis  of  the  spinal  accessory  to  the 

facial  nerve  and  of  the  descendens  hypoglossi  to  the  peripheral  end  of  the  spinal  acces- 
sory.    (Grant's  operation),  Med.  &  Surg.  Rep.  Boston  City  Hosp.,  1913,  p.  190. 
Gushing,  H.:  The  surgical  treatment  of  facial  paralysis  by  nerve  anastomosis   .    .    .  report 

of  a  successful  case,  .-Xnn.  Surg.,  v.  37:   1903,  p.  641. 
D.wiDSON,  A.:  Ueber  die  Nervenpfropfung  im  Gebicte  des  Nervus  facialis,  Beitr.  z.  klin. 

Chir.,  V.  55:  1907,  p.  427- 
Deanesley,  E.:  Two  cases  of  faciohypoglossal  nerve  anastomosis  for  facial  paralysis,  Brit. 

M.  J.,  V.  i:   1913,  p.  1055. 


2l8         SURGICAL   AND    MECHANICAL   TREATMENT   OF    PERIPHERAL   NERVES 

Depage,  a.:  Chirurgie  reparatrice  des  lesions  nerveuses  de  la  face,  J.  de  chir.  et  ann.  Soc. 

beige  de  chir.,  v.  6:  1906,  p.  iii. 
Fagge,   C.   H.:  Inflammatory  facial   paralysis:  facial   accessory  anastomosis,   Proc.   Roy. 

Soc.  Med.  V.  2:  Clin.  Sec.  148,  iqog. 
Faure,  J.  L.:  Traitement  chirurgical  de  la  paralysie  faciale  par  I'anastomose  spinofaciale, 

Rev.  de  chir.,  v.  18:  1898,  p.  1098. 
Fenwick,  G.:  Surgical  treatment  of  facial  paralysis,  Brit.  M.  J.,  v.  2:   1919,  p.  700. 
Fischer,  H.:  Hypoglossal-facial  anastomosis  for  facial  paralysis,  .\nn.  Surg.,  v.  67:   1918, 

p.  627. 
Flourens,  p.:  Recherches  experiment  ales  sur  les  proprietes  et  les  fonctions  du  systeme 

nerveux  dans  les  animaux  vertebras.  Second  Edition,  Paris,  1842. 
Frazier,  C.  H.:  Surgery  of  the  head  and  neck;  the  facial  nerve,  Progr.  Med.,  iMarch,  1914, 

p.  42. 
Frazier,  C.  H.  and  Spiller:  The  surgical  treatment  of  facial  paralysis  (Univ.  Penn.  M. 

Bull.,  Nov.,  1903),  Zentralbl.  d.  Chir.,  no.  5:   1904,  p.  132. 
Galdiz,  J.:  Cinq  cas  de  paralysie  faciale  suivis  d'intervention.  Arch,  internal,  de  laryngol., 

V.  31:  1911,  p.  103. 
Girard:  Traitement  chirurgical  de  la  paralysie  peripherique  du  nerf  facial,  Rev.  med.  de 

la  Suisse  Rom.,  v.  26:  1906,  p.  644. 
Gluck,  Th.:  Nervenplastik  (Greffe  Nerveuse)  nebst  Bemerkungen  iiber  Ubungstherapie 

bei  Liihmungen,  Ztschr.  f.  diatet.  u.  physik.  Therap.,  v.  9:  April  i,  1905,  p.  24. 
Gluge,  G.  and  Thierxesse,  A.:  Sur  la  reunion  des  fibres  nerveuses  sensibles  avec  les 

fibres  motrices.  Bull,  de  I'Acad.  roy'  de  Belgique,  2  me.  serie,  v.  7:  1859,  p.  415. 
Grant,  W.  W.:  Traumatic  facial  paralysis;  anastomosis  of  facial  nerve  to  spinal  accessory, 

and  the  peripheral  end  of  accessory  to  the  descendens  hypoglossi,  J.  A.  M.  A.,  v.  55: 

1910,  p.  1438. 

Halstead,  A.  E.:  The  surgical  treatment  of  facial  paralysis,  Surg.  Clin.  Chicago,  v.  2: 

1918,  p.  227. 
Havre,  van:  Trois  cas  de  lesions  intrapetreuses  du  facial  suivis  d'anastomose  spinofaciale, 

J.  de  chir.  et  ann.  Soc.  beige  de  chir.,  v.  6:   1906,  p.  194. 
Hunt,  R.:  Spinofacial  anastomosis,  with  report  of  a  successful  case,  Pan.  Am.  S.  &  M.  J., 

V.  20:  1915,  7. 
Jaeger,  C.  H.:  Treatment  of  facial  paralysis,  New  York  M.  J.,  v.  109:  1919,  p.  699. 
Johnson',  J.  B.:  Nervous  system  of  vertebrates,  P.  Blakiston's  Son  &  Co.,  Philadelphia,  1906. 
Kennedy,  R.:  On  the  restoration  of  co-ordinated  movements  after  nerve  crossing,  with  the 

interchange  of  function  of  the  cerebral  cortical  centers,  Roy.  Soc.  Proc,  v.  67:  1900, 

p.  431.  (Abstract):  Phil.  Trans.,  B.  v.  194,  1901,  pp.  127-162. 
Experiments  on  the  restoration  of  paralyzed  muscles  by  means  of  nerve  anastomosis, 

Part  I,  substitutes  for  the  facial  nerve.  Phil.  tr.  Roy.  Soc.  London,  Series  B,  v.  202: 

1911,  pp.  93-163. 

Kilvington,  B.:  An  investigation  on  the  regeneration  of  nerves,  Brit.  M.  J.,  v.  i:  1095, 
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Knafp,  p.  C:  Facial  paralysis;  nerve  anaslomosis,  Boston  M.  &  S.  J.,  v.  155:  1916,  p.  644. 
Korte:  Vorslellung  eines  Falles  von  Nervenpfropfung  des  Nervus  facialis  auf  den  Nervus 

hypoglossus,  Freie  Vereinigung  der  Chirurgen  Berlins,   128  Sitzung  am  8  Dez.,  1902; 

Deutsch.  nied.  Wchnschr.,  no.  17,  1903. 
Leiner,  J.  H.:  Study  of  etiological  factors  bearing  on  the  therapeutics  of  Bell's  facial  palsy 

^led.  Rec,  v.  95:   1919,  p.  319. 
Maxasse,  p.:  Ueber  \'ereinigung  des  N.  facialis  mit  deni  N.  accessorius  durch  die  Nerven- 
pfropfung (Greffe  nerveuse),  Arch.  f.  klin.  Chir.,  Berlin,  v.  62:  1900,  p.  805. 
MoRAx,  T.  J.:  Operative  treatment  of  traumatic  paralysis  of  the  sixth  and  seventh  nerves 

with  functional  recovery,  Penn.  M.  J.,  v.  21:  1918,  p.  56S. 
Moure,  E.  J.:  Trois  cas  de  paralysies  faciales  traumatiques  operees,  (abstr.)  in  J.  de  Med. 

de  Bordeaux,  v.  87:  1915-16,  p.  179. 
Paralysie  faciale  de  la  guerre,  Presse  med.,  v.  24:   1916,  p.  161. 
Murphy,  J.  B.:  Facial  nerve  paralysis   .    .    .  spinofacial  nerve  anastomosis;  2  cases,  Surg. 

CHn.  Chicago,  v.  3:  No.  4,  1914,  pp.  745,  751. 
Oppexheim,   H.:  Demonstration  eincs  Falles  von  Facialislahmung  mit   8  Operationsver- 

suchen,  Berl.  klin.  Wchnschr.,  v.  50:   1913,  p.  1585. 
Patrick,  H.  T.:  Three  cases  of  facial  spasms  treated  by  injections  of  alcohol,  J.  Nerv.  & 

Ment.  Dis.,  v.  36:   1909,  p.  1. 
Perret,   C.  a.:  Nerve  anastomosis  for  facial  paralysis,  Schweiz.,  Arch.  f. 

Neurol,  in  Psychiat.,  v.  5:   1919,  p.  141;  abstr.  J.  A.  M.  A.,  v.  74:  Jan.  24,  1920,  p.  291. 
Raxsohoff,  J.:  Traumatic  facial  paralysis,  Ann.  Surg.,  v.  70:  1919,  p.  150. 
S.4RGENT,  p.:  Four  cases  of  facial  paralysis  treated  by  hypoglossofacial  anastomosis,  Proc. 

Roy.  Soc.  Med.,  v.  5:  (Neurol.  Sect.),  1911-1912,  p.  69. 
Sherrex',  J.:  Some  points  in  the  surgery  of  the  peripheral  nerves,  Edinburgh  M.  J.,  v.  20: 

TQo6,  p.  297. 
Stevexs,  R.  H.;  Note  on  a  case  of  anastomosis  between  facial  and  hypoglossal  nerves,  J. 

Roy.  Army  Med.  Corps,  v.  28:  1917,  p.  724. 
Taylor,  A.  S.  and  Clark,  P.  L.:  Results  of  faciohypoglossal  nerve  anastomosis,  J.  A.  M.  A., 

V.  46:  1906,  p.  S56. 
Tubby,  A.  H.:  A  case  of  faciohypoglossal  anastomosis  for  postoperative  paralysis;  nearly 

complete  recovery,  Tr.  Clin.  Soc.  v.  40:   1907.  p.  264;  also,  Proc.  Roy.  Soc.  Med.,  v.  2: 

1909,  (Clin.  Sect.),  p.  145. 
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.•\.,  V.  62:   1914,  p.  612. 


CHAPTER  XI 

UPPER  EXTREMITY 

BRACHIAL  PLEXUS.     THE  RELATION  OF  THE  BRACHIAL  PLEXUS  TO  THE 
DEVELOPMENT  OF  THE  LIMB 

Embryology  of  the  Brachial  Plexus. —  The  morphological  segmental 
arrangement,  such  as  is  found  in  the  trunk  musculature,  is  replaced  in  the  ex- 
tremities by  a  pleurisegmental  arrangement,  so  that  each  muscle  is  innervated 
by  nerves  from  several  segments,  thus  necessitating  the  development  of  plexuses. 
Such  a  pleurisegmental  innervation  obtains  not  alone  for  each  muscle,  but  the 
individual  muscle  tiber  may  possess  a  bisegmental  or  trisegmental  innervation 
as  Agduhr's  (1916-1919)  experiments  in  successive  motor  end  plate  degenera- 
tions have  shown. 

The  formation  of  the  limb  plexuses  and  the  distribution  of  their  branches 
may  be  best  understood  by  considering  the  development  of  the  extremities,  for 
in  the  development  is  found  the  explanation  of  the  division  of  the  spinal  nerves 
into  ventral  and  dorsal  branches  and,  in  general,  their  ultimate  muscular 
distribution. 

In  the  human  embryo  the  limb  buds  appear  at  about  the  third  week.  The 
cephalad  pair  lie  opposite  the  lower  four  cervical  and  first  thoracic  vertebrae  and 
the  caudad  pair  opposite  the  lower  lumbar  and  the  first  sacral.  The  mesoder- 
mal structures  of  the  limb  are  laid  down  in  the  limb  bud  and  do  not  follow  the 
myotomic  segmentation.  The  myotomes  are  present  at  the  axio-appendicular 
junction,  but  do  not  enter  into  the  formation  of  the  limb  buds.  The  limb 
bud  is  developed  from  the  somatopleure  by  proliferation  of  the  cells  lining 
the  coelom  ventrolateral  to  the  myotomes,  the  latter,  according  to  Bardeen 
(1907),  being  separated  from  the  limb  bud  by  a  limiting  membrane.  Lewis 
(1902)  was  unable  to  determine  whether  or  not  some  cells  from  the  myotomes 
migrate  into  the  limb  bud,  though  no  evidence  of  such  migration  was  noted  by 
him  in  his  careful  studies  of  the  development  of  the  human  arm.  The  pectoral 
fin  musculature  in  teleosts,  Harrison  (1895)  found  to  arise  soley  from  the  soma- 
topleure without  any  contribution  from  the  myotomes,  and  similar  conclusions 
were  reached  by  Byrnes  (1898)  in  studing  the  development  of  the  limb  muscles 
in  amphibia.     Only  the  ventral  primary  division  of  the  spinal  nerves  enter  into 


BRACHIAL    PLEXUS 


221 


the  innervation  of  the  Hmb  bud  approximately  five  for  the  upper  extremity  and 
seven  for  the  lower,  thus  indicating  that  the  limb  buds  are  the  outgrowth  from 
a  number  of  segments  and  are  more  closely  associated  with  the  ventral  than 
with  the  dorsal  surface  of  the  body,  since  the  ventral  and  not  the  dorsal  primary 
divisions  of  the  spinal  nerves  are  associated  with  them. 

The  limb  buds  at  first 
present  a  cephalad  or  pre- 
axial  border  and  a  caudad 
or  post  axial  border,  a 
ventral  surface  and  a  dor- 
sal surface.  The  ventral 
surface  corresponds  to  the 
flexor,  the  dorsal  to  the 
extensor  surface  of  the 
primitive  limb.  The  ceph- 
alad or  pre-axial  border 
corresponds  to  the  line  of 
radius  and  thumb,  tibia 
and  great  toe,  the  caudad 
or  postaxial  to  the  line  of 
the  ulna  and  fifth  finger, 
fibula  and  fifth  toe. 

Early  in  its  development 


Musculospiral 

Ulnar 

Median 

Bracliial    Plexus 

Facial 

Circumflex 

Internal  Cutaneous 

Posterior  Interosseus 

Radial 

Suprascapular 

Posterior  Thoracic 

Spinal  Accessory 

Hypoglossal 

Vagus 

Miscellaneous 


Chart  VII. — Table  to  show  relative  frequency  of  nerve  injuries 
of  the  head  and  upper  extremity. 


the  musculature  of  the  limb  bud  presents  two  main  layers,  separated  by 
the  skeletal  anlage  of  the  humerus  into  ventral  and  dorsal  premuscle  masses. 
The  ventral  primary  divisions  of  the  spinal  nerves  which  grow  into  the  limb 
bud  also  separate  into  secondary  ventral  and  dorsal  divisions,  to  supply 
the  ventral  and  dorsal  layers  of  the  limb.  These  secondary  divisions 
correspond  to  the  ventral  and  dorsal  branches  which  form  the  limb  plexus. 
Later  the  ventral  and  dorsal  branches  in  the  limb  bud  unite  with  other 
branches — the  ventral  with  the  ventral,  the  dorsal  with  the  dorsal — thus  con- 
stituting the  ventral  and  dorsal  divisions  of  the  plexus.  The  ventral  branches 
are  distributed  to  the  ventral  musculature,  the  dorsal  to  the  dorsal  musculature. 
However,  with  growth  of  the  limb  buds,  rotation  and  torsion  of  the  humerus 
occurs,  so  that  the  pre-axial  or  cephalad  border  of  the  upper  extremity  is  turned 
laterally  away  from  its  cephalic  position,  thus  rotating  the  structures  on  the 
primitive  ventral  surface  anteriorly  and  those  on  the  primitive  dorsal  surface 


2  22  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

posteriorly.  Consequently  the  anterior  or  ventral  surface  of  the  upper  extrem- 
ity and  shoulder  girdle  represent  the  old  ventral  musculature  and,  therefore, 
should  be  supplied  by  the  branches  of  the  ventral  divisions;  whereas  the  poster- 
ior part  of  the  shoulder  girdle  and  upper  extremity  represent  the  primitive  dorsal 
musculature  and  should  be  innervated  by  the  dorsal  divisions.  This  arrange- 
ment obtains.  The  dorsal  musculature  is  supplied  through  the  subscapular 
circumflex  and  musculospiral  nerves,  made  up  of  dorsal  divisions;  the  ventral 
musculature  through  the  anterior  thoracic  nerves,  median,  ulnar  and  musculo- 
cutaneous nerves  from  the  ventral  divisions. 

Certain  muscles  in  the  primitive  dorsal  or  ventral  musculature  form  by 
fusion  with  either  the  dorsal  or  ventral  musculature  composite  muscles  and, 
therefore,  are  supplied  by  more  than  one  nerve.  If  the  fusion  has  been  of 
different  muscle  masses  in  the  primitive  ventral  musculature,  each  nerve  supply- 
ing such  a  muscle  arises  from  ventral  branches;  and  if  of  dorsal  musculature, 
from  dorsal  branches.  For  example,  the  pectoralis  major  is  supplied  by  the 
external  and  internal  anterior  thoracic  nerves  and  the  flexor  profundus  digi- 
torum  by  the  median  and  ulnar  nerves.  However,  such  muscles  as  the  brach- 
ialis  in  the  upper  extremity,  biceps  in  the  lower  extremity  represent  a  fusion 
along  the  pre-axial  or  post-axial  border  of  the  primitive  musculature  derived 
from  both  ventral  and  dorsal  layers,  and  consequently  are  supplied  by  two 
sets  of  nerves,  one  arising  from  ventral  and  the  other  from  dorsal  branches. 
This  is  seen  in  the  supply  of  the  brachialis  in  which  the  musculospiral  nerve 
(dorsal  divisions)  and  the  musculocutaneous  (ventral  divisions)  both  participate. 

Anatomical  Considerations  of  the  Brachial  Plexus. — Considerable  variance 
in  the  number  of  spinal  segments  which  enter  into  the  formation  of  the  brachial 
plexus  exists  and  variation  in  the  particular  segmental  supply  of  the  muscles  is 
often  found,  which  has  led  to  no  little  perplexity  in  more  careful  attempts  to 
determine  the  exact  location  of  certain  lesions  by  means  of  the  more  usual 
anatomical  segmental  distribution.  Accurate  localization  of  paralysis  of  the 
brachial  plexus  is  frequently  difficult  due  to  the  complexity  of  the  component 
fibers  of  the  nerve  roots  and  to  the  presence  of  numerous  branches  close  together 
which  may  be  implicated  at  one  point  and  the  main  nerve  roots  at  another. 
Almost  any  combination  may  exist  and  only  by  clear  and  concise  anatomical 
interpretation  may  the  level  of  the  lesion  be  placed. 

Anatomically  there  are  two  main  types  of  plexuses — prefixed  and  post- 
fixed — the  former  having  a  high  cervical  origin  and  the  latter  a  low  cervical 
origin.     In  the  prefixed  plexus  a  large  part  of  the  fourth  cervical  root  joins 


BRACHIAL    PLEXUS 


223 


the  plexus  instead  of  just  a  small  twig  of  communication.  There  is  less  of 
the  first  thoracic  root  with  no  branch  of  communication  from  the  second 
thoracic.  In  the  postlixed  there  is  no  branch  from  tlie  fourth  cervical  root. 
The  first  thoracic  contributes  largely  to  the  formation  of  the  inner  cord  and 
a  branch   from   the  second  thoracic  always  joins  the  plexus.     Thus,  there  is 


^''  ■'>,- 


Fig.  84. — Prefixed  type  of  plexus.  The  connective  tissue  sheaths  of  the  nerves  are  all  dissected 
oflt,  and  thus  the  posterior  and  outer  cords  are  seen  resolved  into  their  component  parts.  The  branch 
to  the  outer  cord  from  S-6C  has  been  divided  in  order  to  show  the  origin  of  the  nerve  to  the  coraco- 
brachialis;  the  branch  from  8C  to  the  inner  cord  has  also  been  similarly  divided  to  show  the  posterior 
branch  of  iD.  Xote  the  large  size  of  the  outer  head  of  the  ulnar,  piercing  directly  through  the 
inner  head  of  the  median.  Note  also  that  the  inner  head  of  the  median  is  given  off  from  the  lower 
and  anterior  portion  of  the  inner  cord,  and  passes  in  front  of  the  ulnar,  which  is  given  off  from  the 
posterior  bundles  of  the  inner  cord.     (Harris,  Jour.  .A.nat.  &  Physiol.) 

more  or  less  shifting  cephalad  or  caudad  of  approximately  one  segment  in  the 
origin  of  the  plexus — a  condition  analogous  to  that  found  by  Eisler  (1892)  in  the 
himbar  plexus.  This  variation  in  the  segmental  contribution  to  the  plexus 
may  be  explained  by  the  fact  that  the  nerves  and  the  particular  segments  which 
contribute  to  the  innervation  of  the  limb  bud  is  determined  by  the  width  of  the 
l)Ufi  and  its  relation  to  the  neural  axis.     The  presence  of  the  developing  limb 


2  24         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

bud  appears  to  be  an  attraction  for  and  a  stimulus  to  the  adjacent  nerve  fibers. 
By  transplanting  limb  buds  in  amphibian  embryos  to  other  and  foreign  parts 
of  the  embryo  Harrison  (1907)  was  able  to  show  that  a  new  segmental  innerva- 
tion of  the  limb  bud  occurred  with  formation  of  new  nerve  plexuses  by  netves 


Fig.  85. — Postfixed  type  of  plexus.  In  this  case  the  nerve  sheaths  have  not  been  dissected 
off  the  posterior  cord,  but  the  outer  cord  has  been  dissected  to  show  the  origin  of  the  nerve  to  the 
coracobrachialis  from  7-8C.  Note  the  small  size  of  sC,  and  also  the  tine  recurrent  branch  which 
leaves  the  accessory  outer  head  of  the  median,  and  perforates  the  inner  head  of  the  median  to  form 
the  outer  head  of  the  ulnar.     (Harris,  Jour.  .\nat.  &  Physiol.) 

which  normally  never  enter  into  the  supply  of  the  extremities.     Embryologi- 

cally  the  arm  and  leg  buds  show  considerable  variation  in  their  relative  position 

to  the  vertebral  column,  varying  as  many  as  two  or  three  segments,  and  their 

spinal  nerves   varying   accordingly.     Thus   more   cephalac   nerves  form   the 

plexus  when  the  limb  has  a  more  cephalic  position,  and  vice  versa.     Harris 

(1903)  seems  to  think  that  in  the  higher  forms  the  more  cephalic  position  is 

more  common. 

Harris  has  pointed  out  that  this  variance  manifests  itself  in  the  relative 


BRACHIAL    PLEXUS  225 

contribution  which  each  segment  makes  to  the  nerve  branches  of  the  plexus, 
particularly  in  those  branches  formed  by  fibers  from  either  the  upper  cervical 
roots  or  the  eighth  cervical  and  first  thoracic,  i.e..  either  the  cephalic  or  caudad 
extremity  of  the  plexus.  According  to  Harris,  in  the  prefixed  plexus  (see  Fig. 
84)  neither  the  suprascapular  nerve  nor  the  circumflex  receives  fibers  from  the 
sixth  cervical,  so  that  the  supraspinatus  and  infraspinatus,  the  deltoid  and  teres 
minor  muscles  receive  their  supply  from  the  fourth  and  fifth  cervical.  The  fifth 
root  is  large  and  equal  in  size  to  the  sixth,  and  contains  more  motor  than  sensory 
fibers.  This  fact  has  been  confirmed  by  Warrington  and  Jones  (1906)  and  by 
one  of  the  author's  cases.  The  sensory  loss  is  relatively  small  when  the  fifth 
root  alone  is  involved,  the  area  being  considerably  less  than  one-half  that 
usually  found  when  both  the  fifth  and  sixth  are  implicated. 

In  the  postfixed  plexus  (see  Fig.  85),  the  suprascapular  and  the  circumflex 
nerve  is  made  up  from  both  the  fifth  and  sixth  cervical.  The  nerve  to  the 
coracobrachialis  obtains  its  fibers  from  the  seventh  alone,  whereas  in  the 
prefixed  plexus  the  latter  receives  its  supply  from  the  sixth  cervical.  The 
accompanying  tables  of  Harris  (pp.  226  and  227)  give  in  detail  the  muscular 
supply  in  ijoth  the  prefixed  and  postfixed  plexuses.  In  certain  cases  such 
a  table  may  aid  in  formulating  a  more  precise  localization  or  assist  in  eluci- 
dating some  obscure  types  of  paralyses. 

Anatomical  TjT)es  of  Brachial  Plexus  Injuries. — Care  must  be  taken  to 
avoid  interpreting  a  plexus  lesion  in  terms  of  peripheral  nerve  trunk  paralysis. 
Plexus  lesions  are  radicular  in  their  distribution  and  not  truncular.  The 
nerve  root  is  a  morphological  unit ;  the  nerve  trunk  a  physiological  unit.  Stimu- 
lation of  the  former  produces  contraction  of  asynergic  units  (flexors  and  exten- 
sors), whereas  stimulation  of  the  nerve  trunk  evokes  simultaneous  contraction 
of  synergic  units.  In  general,  it  may  be  said  that  injuries  above  the  clavicle 
invcilve  the  nerve  roots,  the  primary  cords,  either  single  or  multiple,  or  the 
muscular  branches  which  arise  from  the  nerve  roots  and  primary  cords;  while 
injuries  below  the  cia\'icle  implicate  the  secondary  cords  and  their  branches, 
and  correspond  in  the  main  to  injuries  of  two  or  more  of  the  peripheral  nerves, 
such  as  a  lesion  in  the  outer  secondary  cord,  which  would  involve  the  musculo- 
cutaneous and  the  outer  head  of  the  median  ner\-e. 

The  branches  from  the  nerve  roots  are  the  dorsalis  scapula.'  (nerve  to  the 
rhombodeii  and  levator  angulii  scapula;)  and  the  long  thoracic  nerve  to  the 
serratus  magnus,  while  those  from  the  primary  cords  at  their  formation  and, 
therefore,  still  supraclavicular,  are  the  suprascapuhir  nerve  to  the  supra-  and 


2  26         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

MOTOR  ROOT  SUPPLY  OF  MUSCLES  OF  UPPER  EXTREMITY 
Prefixed  Type  of  Plexus 

4-5  C.  Deltoid 

Teres  minor 

Supraspinatus 

Infraspinatus 

5  C.  Rliomboids 

Subclavius 
Biceps 

Brachialis  anticus 
Supinator  longus 
Supinator  brevis 
Pronator  radii  teres 
Extensor  carpi  radialis  longior 
Extensor  carpi  radialis  brevier 

5—6  C.  Pectoralis  major  clavicular 

Subscapularis 

5-6-7  C.  Serratus  magnus 

Triceps 

6—7  C.  Teres  major 

Coracobrachialis 
6-7-8  C.  Pectoralis  major  (sternal) 

Latissimus  dorsi 

Extensor  carpi  ulnaris 

Flexor  carpi  radialis 

7—8  C.  Pectoralis  minor 

Flexor  carpi  ulnaris 
Extensor  communis  digitorum 
Extensor  ossis  metacarpi  pollicis 
Extensor  primi  internodii  pollicis 

8  C.-i  D.  Extensor  secundi  internodii  pollicis 

Extensor  indicis 
Extensor  minimi  digiti 
Pronator  quadratus 
Palmaris  longus 
Flexor  sublimis  digitorum 
Flexor  longus  pollicis 
Flexor  profundus  digitorum 

I  D.  Thenar  muscles 

Lumbricals 
Interossei 
Hypothenar  muscles 

MOTOR  ROOT  SUPPLY  OF  MUSCLES  OF  UPPER  EXTREMITY 
PosTFDCED  Type  of  Plexus 

S  C.  Deltoid 

Teres  minor 


BRACHIAL  PLEXUS  227 

Supraspinatus 
Infraspinatus 
Rhomboids 
Subclavius 


5-6  C.  Biceps 

Brachialis  anticus 


Supinator  longus 
Supinator  brevis 
Pronator  radii  teres 
Extensor  carpi  radialis  longior 
Extensor  carpi  radialis  brevier 
Pectoralis  major  (clavicular) 

5-6—7  C.  Subscapularis 

Serratus  magnus 

6-7  C.  Triceps 

Teres  major 

6-7-8  C.  Pectoralis  major  (sternal) 

Latissimus  dorsi 

7—8  C.  Pectoralis  minor 

Coracobrachialis 
Extensor  carpi  ulnaris 
Flexor  carpi  radialis 
Extensor  communis  digitorum 

8  C.-i  D.  Flexor  carpi  ulnaris 

Extensor  ossis  metacarpi  poUicis 

Extensor  primi  internodii  pollicis 

Extensor  secundi  internodii  pollicis 

Extensor  indicis 

Extensor  minimi  digiti 

Pronator  quadratus 

Palmaris  longus 

Flexor  sublimis  digitorum 

Flexor  longus  pollicis 

Flexor  profundus  digitorum 

i-^  D.  Thenar  muscles 

Lumbricals 
Interossei 
Hypothenar  muscles 

infraspinatii,  the  subclavian  nerve  to  the  subclavius  muscle  and  those  to  the 
scalenii.  All  other  branches  are  infraclavicular.  The  uppermost  of  these  are 
the  anterior  thoracic  and  subscapular  nerves,  which  arise  from  the  secondary 
cords  just  j)rior  to  their  ultimate  di\ision  to  form  the  nerves  of  the  extremity. 


2  28         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

As  there  are  three  cords  to  the  brachial  plexus,  so  there  are  three  main 
types  of  paralysis  which  may  result  from  injury  to  the  brachial  plexus  above  the 
clavicle.  They  are  the  upper  cervical,  or  Duchenne-Erb,  the  middle,  and  the 
lower  or  Duchenne-Aran.  These  are  the  three  classical  types,  but  injuries 
to  the  roots  of  the  plexus  may  occur  in  almost  any  combination.  The  upper 
cervical  is  the  more  common,  due  perhaps  to  the  greater  length  and  exposure  of 
the  fifth  and  sixth  cervical  nerve  roots. 

It  follows  that  in  injuries  to  the  brachial  plexus  above  the  clavicle,  paraly- 
sis is  looked  for  in  some  of  the  muscles  of  the  shoulder  girdle,  particularly  the 
rhombodeii,  levator  angulii  scapulae,  serratus  magnus,  supraspinatus,  and 
infraspinatus,  though  some  of  these  may  escape  depending  upon  the  exact 
location  of  the  lesion;  while  in  injuries  below  the  clavicle,  these  muscles  of  the 
scapula  are  not  involved. 

It  is  important  to  localize  plexus  lesions  with  precision,  and  to  rule  out 
injury  affecting  one  or  more  segments  of  the  spinal  cord,  especially  such  as 
involve  the  ventral  horns.  It  will  be  recalled  that  spinal  nerves  divide  almost 
immediately  after  their  formation  into  a  primary  dorsal  and  primary  ventral 
division;  the  former  supplies,  besides  the  dorsal  axial  musculature,  the  skin 
over  the  dorsum  in  a  region  bounded  laterally  by  a  line  running  from  the  mid- 
parietal  region  to  the  mastoid,  acromion,  trochanter  and  coccyx.  From  this 
distribution  of  the  sensory  branches  of  the  dorsal  primary  divisions,  it  follows 
that  if  a  lesion  lies  immediately  outside  the  spinal  cord  there  would  be,  as  well 
as  the  other  signs  of  injury,  an  area  of  anesthesia  to  all  forms  of  sensation  over 
the  region  of  the  back  supplied  by  the  primary  dorsal  divisions,  which  would  not 
be  found  if  the  lesion  were  distal  to  the  primary  dorsal  division  of  the  spinal 
nerve.  Division  of  the  nerve  takes  place  in  or  close  to  the  intervertebral 
foramina.  On  the  other  hand,  if  the  lesion  in  the  nerve  is  at  any  point  distal 
to  the  dorsal  primary  division,  the  dorsal  division  escapes  and  no  sensory 
changes  are  found  in  the  area  on  the  dorsum  as  above  described.  In  making 
this  differential,  we  must  rely  upon  sensory  rather  than  motor  changes  for  the 
axial  musculature  has  lost  its  segmental  character  as  a  result  of  a  fusion  into  a 
common  muscular  mass  having  a  common  motor  supply,  and  hence  isolated  seg- 
mental paralysis  is  rarely  to  be  observed.  On  the  other  hand,  if  the  lesion  be  in 
the  ventral  gray  column,  obviously  no  sensory  loss  will  be  found  in  the  distribu- 
tion of  either  the  ventral  or  the  dorsal  divisions.  It  must  also  be  remembered 
that  in  the  formation  of  the  limb  plexus  certain  nerves  have  lost  their  primary 
dorsal  cutaneous  divisions  and  consequently  have  no  representation  in  the  sen- 


BRACHIAL   PLEXUS  229 

sory  supply  on  the  dorsum.  This  loss  usually  occurs  in  the  nerves  which  lie  in 
the  central  portion  of  the  plexus  and  supply  the  most  distal  portion  of  the 
extremity;  these  are  the  seventh  and  eighth  cervical  nerves  in  the  brachial 
plexus  and  the  fourth  and  fifth  lumbar  in  the  lumbosacral  plexus. 

If  these  anatomical  considerations  be  remembered,  more  accurate  diagnosis 
may  be  made  in  plexus  lesions,  particularly  if  the  individual  action  of  the 
muscles  of  the  shoulder  girdle  be  studied.  Unless  correct  interpretation  of  the 
movements  is  made  finer  localization  is  not  possible.  However,  the  individual 
action  of  these  muscles  is  difficult  to  evaluate  since  they  form  a  synergic  group 
having  a  wide  origin  and  capable  of  independent  contraction  in  different  parts 
of  the  muscle,  each  of  which  may  serve  different  or  even  opposed  actions.  In 
order  that  their  action  may  be  better  understood  it  might  be  well  to  review 
here  the  physiological  mechanism  and  action  of  the  more  important  shoulder 
girdle  muscles  which  serve  in  elevation  of  the  humerus.  The  movements  of 
the  muscles  in  the  arm,  forearm  and  hand  are  relatively  simple  and  need  not  be 
given  here. 

Mechanism  of  Shoulder  Girdle  Movements. — The  generally  accepted 
view  that  in  raising  the  humerus  to  a  straight  angle  the  deltoid  elevates  the 
arm  approximately  to  a  right  angle,  after  which  the  deltoid  no  longer  acts  and 
elevation  is  completed  by  scapular  rotation,  is  not  supported.  It  has  been 
found  that  the  deltoid  alone  is  unable  to  raise  the  humerus  beyond  60°  and  that 
elevation  from  this  to  approximately  115°  involves  scapular  rotation,  after 
which  the  deltoid  again  becomes  active  and  completes  the  elevation.  (See 
Fig.  86  and  Figs.  87.) 

If  the  arm  is  considered  in  its  position  in  different  stages  of  elevation,  it  will 
be  seen  that  the  origin  and  insertion  of  the  deltoid  are  placed  so  that  it  may  serve 
this  dual  function  of  abductor  and  adductor.  Two  muscles  whose  action  in 
elevation  has  been  ignored  may  serve  as  supplementary  factors  of  no  small 
importance  in  the  accomplishment  of  the  final  stage  of  elevation.  They  are 
the  clavicular  head  of  the  pectoralis  major  and  the  coracobrachialis  muscles. 
These  muscles  are  brought  into  play  particularly  when  great  force  in  elevation 
is  demanded,  or  when  there  is  some  impairment  in  the  normal  function  of 
the  deltoid  or  of  the  muscles  which  fix  and  rotate  the  scapula.  Normally 
this  function  of  the  clavicular  head  of  the  pectoralis  major  may  be  brought  out 
by  forcible  resistance  to  elevation  or  by  sudden  attempts  to  lower  the  arm 
from  elevation.  The  clavicular  jiortion  of  the  pectoralis  major  will  be  seen  to 
take  active  ])art  in  forcible  elevation  above  115°  or  in  efforts  to  oppose  lowering 


230         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL   NERVES 

the  elevated  arm  to  115.°     The  clavicular  portion  of  the  pectoralis  major  serves 
a  function  similar  to  that  of  the  clavicular  portion  of  the  deltoid. 


O"  5°  0° 

Fig.  S6. — Tracings  of  the  scapula  and  humerus  showing  their  relation  in  elevation  of  the 
humerus.  It  will  be  noted  that  the  greatest  scapular  rotation  takes  place  between  the  60th  and  the 
115th  degrees  of  elevation  of  the  humerus.     (Stookey,  Archiv.  Neur.  Psych.,  1920.) 

In  this  connection  it  is  interesting  to  note  that  phylogenetically  the  clav- 
icular head  of  the  pectoralis  major  is  present  only  as  such  in  the  higher  forms 
particularly  the  chimpanzee  and  the  gibbon,  while  in  all  other  primates,  as  well 
as  the  lower  mammals,  it  is  wanting.  In  them  the  pectoralis  major  arises 
from  the  manubrium  and  does  not  reach  to  the  clavicle.     However,  in  those 


BRACHIAL    PLEXUS 


231 


forms  in  which  there  is  no  clavicular  head  of  the  pectoralis  major,  the  clavicu- 
lar portion  of  the  deltoid  extends  medially  upon  the  clavicle  up  to  the  origin  of 
the  sternocleidomastoid.  The  clavicular  portion  of  the  pectoralis  major 
may  be  considered  as  a  migration  of  the  innermost  muscular  libers  of  the  clav- 
icular head  of  the  deltoid.  This  view  is  perhaps  further  sustained  by  the  nerve 
supply  of  the  clavicular  portion  of  the  'pectoralis  major  which  occasionally  is 
supplied  by  a  twig  from  the  circumflex,  thus  having  the  same  nerve  supply  as 
the  deltoid.  In  the  embryological  development  of  the  pectoralis  major  the 
sternal  and  clavicular  portions  are  distinct  and  separated  by  a  considerable 
interval. 


TOTKL-    bU 


Fig.  87. — Schematic  drawing  to  show  relation  of  the  scapuhi  to  the  humerus  in  elevation  of  the 
humerus.  Dotted  lines  indicate  scapular  rotation  during  the  various  phases  of  elevation.  With 
elevation  of  the  humerus  to  60°  the  scapula  rotates  5°;  with  elevation  of  the  humerus  from  60°  to 
[15°  the  scapula  rotates  35°,  and  with  elevation  from  115°  to  180°  scapula  rotation  is  10°.  The 
major  part  of  elevation  of  the  humerus  in  this  last  phase  is  done  by  the  deltoid.  (Stookey,  Archiv. 
Neurol.  &  Psych.,  1920.) 

It  is  not  surprising,  but  rather  to  be  expected,  that  the  clavicular  head 
of  the  pectoralis  major  should  resume  its  former  association  and  along  with  the 
clavicular  head  of  the  deltoid  serve  in  part,  at  least,  a  like  function,  namely, 
as  an  elevator  of  the  humerus  from  above  115°. 

Thus  shoulder  girdle  movements  may  be  extremely  misleading  and  false 
localizations  reached  unless  an  accurate  analysis  is  made. 


PARALYSIS  OF  THE  BRACHIAL  PLEXUS 

As  has  already  been  mentioned  there  are  in  general  three  types  of  paralysis 
of  the  brachial  plexus:  the  upper  radicular,  middle  and  lower;  between  these 
forms  variations  occur  depending  upon  the  degree  and  extent  of  the  injury. 


232  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

The  upper  radicular  or  Ducherme-Erb  type  involves  the  fifth  and  sixth 
cervical  roots,  the  lesion  being  more  often  at  the  junction  of  these  two  and  in- 
cluding the  suprascapular  nerve  at  its  origin,  whereas  if  the  lesion  is  closer  to 
the  exit  of  the  roots  from  the  vertebral  canal,  the  dorsalis  scapulas  and  posterior 
thoracic  nerves  may  be  involved.  Thus,  if  the  lesion  is  near  the  exit  of  the 
nerve  roots  from  the  intervertebral  foramina  the  rhombodeii,  levator  scapulae, 
and  the  major  portion  of  the  serratus  magnus  are  paralyzed  whereas,  if  the 
injury  is  more  distal,  these  muscles  may  escape  and  the  axio-appendicular 
muscles  be  implicated — the  supraspinatus  and  infraspinatus,  teres  minor  and 
the  deltoid.  The  muscles  involved  in  the  arm  are  the  biceps,  brachialis,  and 
the  supinator  longus;  those  in  the  forearm  are  the  pronator  teres,  flexor  carpi 
radialis,  palmaris  longus  and  the  supinator  brevis.  This  forearm  group  is 
generally  incompletely  paralyzed  due  to  the  fact  that  some  of  their  motor 
supply  is  received  from  lower  segments.  Thus  the  deformity  in  injury  of  the 
fifth  and  sixth  cervical  roots  may  be  extensive,  not  only  in  its  distribution,  but 
in  its  motor  effect,  particularly  if  the  lesion  be  near  the  vertebral  canal  so 
as  to  include  the  posterior  thoracic  and  dorsalis  scapulae  nerves.  If  the  shoulder 
girdle  muscles  are  involved,  the  scapula  is  winged,  and  the  inferior  angle 
rotated  so  that  it  looks  toward  its  fellow  of  the  opposite  side.  The  scapula 
cannot  be  approximated  and  rotation  necessary  for  elevation  of  the  arm  is  lost. 
With  time  the  scapular  deformity  becomes  accentuated,  the  acromion  is  bent 
downward  and  forward  and  may  hook  in  front  of  the  head  of  the  humerus  if  the 
latter  is  subluxated.  Perhaps  this  deformity  is  due  to  the  fact  that  this  bone 
does  not  meet  the  resistance  of  the  humerus  which  normally  is  present  during 
its  various  phases  of  movement.  Since  the  scapula  can  not  be  tLxed  the 
deltoid  does  not  have  a  fixed  point  of  action,  a  consideration  which  must  be 
borne  in  mind,  and  the  scapula  manually  supported  when  the  deltoid  is  being 
re-educated  in  the  early  stages  of  recovery.  It  will  be  recalled  that  by  develop- 
ment of  the  serratus  magnus  and  trapezius  the  movements  of  the  scapula  may 
be  made  to  compensate  and  take  on,  to  a  considerable  degree,  the  function  of 
elevation  of  the  arm.  Hence,  in  injuries  involving  both  the  serratus  magnus, 
rhombodeii  and  levator  scapulae,  as  well  as  the  deltoid  and  supraspinatus,  the 
range  of  movement  left  is  almost  nil. 

DefortnUy. — In  this  paralysis  the  arm  is  found  in  adduction  due  to  paraly- 
sis of  the  supraspinatus  and  deltoid;  in  internal  rotation  due  to  paralysis  of 
the  spinatii  and  teres  minor,  particularly  the  infraspinatus,  and  the  unopposed 
action  of  the  subscapular  and  pectoralis  major.     Internal  rotation  can  be  only 


BRACHIAL   PLEXUS 


233 


partially  performed  since  the  internal  rotators  are  unopposed  in  their  action 
and  are  already  in  a  state  of  contraction.  The  forearm  is  held  semi-extended 
and  in  pronation  with  inability  to  flex  it  due  to  paralysis  of  the  biceps,  brachialis 
and  supinator  longus.  The  palm  of  the  hand  faces  backward  due  to  total 
inward  rotation  of  the  extremity  and  extreme  pronation.  The  grip  of  the 
hand  is  fairly  good. 


Fig. 


Fir..  8q. 


Fig.  88. — .Adjustable  abduction  splint  with  adjustable  forearm  piece  for  paralysis  of  the  outer 
cord  of  the  brachial  plexus.  Thc>  arm  is  held  in  abduction  and  exicrnal  rotation  with  the  hand 
in  supination.  By  altering  the  pin  and  lever,  the  arm  can  be  held  at  any  desired  angle  of  abduction. 
The  forearm  piece  may  also  be  adjusted  by  a  screw  lock  to  various  degrees  of  flexion.  The  splint 
is  made  of  aluminum  and  lined  with  felt.     (Stookey,  Surg.,  Gyn.  and  Obst.,  Nov.,  1918.) 

Fig.  89. — .\bduction  splint  for  infants.  The  splint  consists  of  a  padded  aluminum  piece  ex- 
tending from  the  hip  to  the  axilla,  elbow  and  hand,  with  cross  pieces  to  which  tapes  are  fastened. 
The  angle  of  abduction  may  be  altered  by  bending  the  metal  at  the  axilla.  (Stookey,  Surg.  Clin. 
N.  .'\m.,  IQ2I.) 

T/ie  mechanical  treatment  of  this  deformity  recjuires  that  two  distinct 
postures  be  obtained:  first,  abduction  to  relax  the  deltoid  and  supraspinatus; 
second,  the  one  most  often  overlooked,  external  rotation  in  order  to  overcome, 
the  powerful  contraction  of  the  internal  rotators,  particularly  the  pectoralis 
major,  the  latissimus  dorsi  and  subscapularis.  In  old  and  neglected  cases 
these  muscles  are  contracted,  preventing  both  elevation  and  external  rotation 
of  the  arm,  and  require  tenotomy  in  order  that  the  arm  may  be  raised  and 
placed  in  external  rotation.  The  arm  should  be  held  in  abduction  about 
70  to  80  degrees,  and  in  the  midcoronal  plane,  so  as  to  relax  the  calvicular 
and  scapular  portions  of  the  deltoid.     Complete  abduction  to  90  degrees  is 


234         SURGICAL   AND   MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 

extremely  awkward  and  in  cases  in  which  permanent  deformity  due  to  con- 
comitant bony  injuries  may  occur,  it  is  a  position  of  least  service.  In  addition 
to  abduction,  the  arm  must  be  held  in  external  rotation  with  the  forearm 
somewhat  flexed  upon  the  arm  and  the  forearm  held  in  supination  so  that  the 
hand  is  turned  toward  the  face.  Care  must  be  taken  to  assure  the  arm  being 
in  external  rotation,  for  occasionally,  with  the  hand  in  supination,  the  arm 
may  appear  to  be  rotated  externally,  while  in  reality  the  forearm  only  is  held 
in  extreme  supination. 

Numerous  splints  have  been  designed  to  serve  the  above  requirements  of 
abduction  and  external  rotation,  any  one  of  which  will  be  found  satisfactory. 
In  adults  it  is  preferable  to  have  the  chest  piece  of  the  splint  continue  down- 
ward so  as  to  rest  upon  the  crest  of  the  ileum,  making  it  serve  to  support  the 
weight  of  the  extremity.  In  infants,  a  light  plaster  or  metal  splint  is  satis- 
factory. A  plaster  splint  is  first  applied  as  a  complete  plaster  and  afterwards 
removed  and  part  of  it  cut,  i.e.,  the  chest  piece  split  and  part  removed  so  that 
it  can  be  strapped  and  readily  removed  for  bathing,  etc.  The  arm  piece  is 
cut  out  so  that  it  forms  merely  a  gutter  in  which  the  arm  and  the  foreaim  are 
held  by  broad  straps,  or  the  plaster  may  be  applied  as  a  gutter  splint,  and  the 
edges  merely  trimmed.  By  baking,  the  splint  may  be  made  very  hard  and 
durable  so  that  less  plaster  is  recjuired.  The  illustrations  of  the  metal  splints 
shown  in  Figs.  88  and  89  are  in  themselves  explanatory  and  do  not  need  any 
further  description. 

The  Middle  Radicular. — In  paralysis  of  the  seventh  cer\'ical  root  muscles 
which  characterize  total  musculospiral  injury  as  well  as  the  coracobrachialis 
are  involved  with  the  exception  of  the  supinator  longus  and  the  deltoid.  The 
nerve  to  the  coracobrachialis  muscle  arises  as  a  separate  nerve  from  the  seventh 
root  and  passes  as  a  separate  nerve  or  is  incorporated  in  the  sheath  of  the 
musculocutaneous.  The  latissimus  dorsi,  subscapularis,  teres  major  are  par- 
alyzed, the  triceps  only  partially  since  it  receives  some  fibers  from  the  sixth 
cervical,  and  in  the  prefLxed  plexus  from  the  fifth  cervical.  Slight  ability  to 
dorsiflex  the  wrist  may  be  retained,  since  the  extensors  of  the  wrist  also  receive 
part  of  their  supply  from  the  sixth  and  even  the  fifth  cervical  nerves. 

The  deformity  and  mechanical  treatment  of  this  injury  is  similar  to  that 
given  for  paralysis  of  the  musculospiral  and  will  be  considered  under  the  treat- 
ment of  that  nerve. 

The  lower  radicular  or  Duchenne-Aran  type  involves  the  last  cervical 
and  first  thoracic  nerves.     The  paralysis  is  limited  in  its  distribution  to  the 


BRACHIAL    PLEXUS  235 

ulnar  side  of  the  forearm,  and  to  the  intrinsic  muscles  of  the  hand,  with  the 
exception  that  occasionally  the  abductor  pollicus  and  the  opponens  pollicis  are 
not  included,  since  these  muscles  may  receive  some  fibers  from  the  fifth  and 
sixth  cervical  roots.  It  is  noteworthy  that  injuries  which  involve  the  fifth  and 
sixth  cervical  nerves  rarely  cause  paralysis  of  the  opponens,  presumably  supplied 
l)y  the  fifth  and  sixth  cervical  segments.  In  only  one  instance  have  I  seen  the 
opponens  escape  in  lower  radicular  lesions,  so  that  it  would  seem  that  perhaps 
the  opponens  only  occasionally  receives  fibers  from  the  fifth  and  sixth  cervical 
nerves. 

In  the  forearm  the  flexor  carpi  ulnaris,  flexor  profundus  and  flexor  digitor- 
umi  sublimis,  as  well  as  the  flexor  pollicis  longus  are  paralyzed.  As  would  be 
expected  the  resulting  deformity  is  in  the  hand  and  on  the  ulnar  or  post-axial 
border  of  the  forearm.  The  hand  appears  as  a  flattened  Simian  hand,  resem- 
bling closely  that  found  in  combined  injuries  of  the  median  and  ulnar  nerves. 
Adduction  of  the  hand  is  lost,  flexion  at  the  wrist  is  impaired,  but  can  be 
accomplished  by  the  flexor  carpi  radialis,  while  flexion  of  the  fingers,  abduction 
of  the  fifth  finger,  and  opponens  action,  as  well  as  extension  of  the  distal  two 
phalanges  of  the  fingers,  arc  impossible. 

If  this  deformity  is  not  adequately  treated  mechanically,  contractures  are 
likely  to  occur,  and  in  neglected  cases  fixed  subluxations  of  the  interphalangeal 
joints  may  be  found.  For  the  mechanical  treatment,  a  straight  splint  with 
groovesfor  each  finger  permitting  movements  at  the  metacarpo-phalangeal  and 
interphalangeal  joints  offers  the  most  satisfactory  treatment.  The  splint  should 
be  made  of  the  Kghtest  possible  material.  (See  Figs.  138-139.)  The  joints  of  the 
fingers  should  be  put  through  their  range  of  motion  daily  in  order  to  avoid 
contractures  about  the  joint  capsules.  One  of  the  most  satisfactory  forms  of 
exercise  for  older  children  and  adults  is  the  Zander  finger  and  wrist  machines. 
By  this  means  the  muscles  and  joints  may  be  put  through  the  greater  part  of 
their  normal  contraction  and  range  of  motion. 

Obstetrical  Paralysis 

Rupture  of  the  brachial  plexus  occurs  not  only  during  childbirth  but  in 
adult  life  as  well.  In  both  the  injury  is  the  result  of  mechanical  forces  similarly 
applied,  showing  similar  paralyses  and  similar  pathology  in  the  nerve  trunks  of 
the  plexus. 

In  lesions  so  readily  demonstrable  as  those  found  in  birth  palsies  it  seems 
strange  that  there  should  be  two  opposed  views  concerning  the  pathological 


236         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

changes  encountered;  some  claiming  that  the  deformity  is  primarily  of  bony 
origin,  or  due  to  a  lesion  in  the  capsule  of  the  shoulder  joint;  and  others,  that 
the  injury  is  primarily  to  the  nerve  roots  wliich  form  the  brachial  plexus.  As  a 
result  of  these  different  opinions  an  attitude  of  laissez  faire  has  been  frequently 
adopted  and  many  times  nothing  is  done  by  way  of  treatment.  Generally  the 
mother  is  told  that  the  paralysis  will  disappear  in  time.  No  doubt  a  few  of  the 
lesser  injuries  recover  untreated,  but  the  more  severe  do  not. 

Brachial  plexus  injuries,  due  to  pulling  apart  of  the  nerve  trunks,  differ  from 
other  nerve  injuries  not  only  in  etiology  and  pathology  but  also  in  the  results 
obtained  by  their  surgical  treatment.  This  difference  is  due  to  the  fact  that 
the  nerve  fibers  and  funiculi  are  torn  apart  and  not  simply  crushed  or  cut  in  one 
place.  When  the  plexus  has  been  overstretched  the  funiculi  break  and  this 
break  may  occur  at  any  point  from  the  origin  of  the  roots  from  the  spinal 
cord  to  the  most  distal  point  of  the  injury.  Hence  some  funiculi  may  be 
evulsed  from  the  spinal  cord  and  others  torn  apart  within  the  nerve  trunk. 
Consequently,  at  any  cross  section  within  the  nerve  scar  the  injury  is  irregular 
and  incomplete.  Such  an  anatomical  arrangement  makes  it  difficult  to  deter- 
mine at  what  level  excision  of  the  scar  can  be  made  so  as  to  obtain  normal 
funiculi.  The  different  funiculi  may  be  interrupted  in  more  than  one  place,  and 
this  not  recognized  at  the  area  at  which  suture  is  done.  Funiculi  evulsed  from 
the  spinal  cord  cannot  be  repaired;  those  torn  only  more  distally  may  be 
successfully  sutured. 

Historical. — The  early  writers  considered  paralysis  at  birth  to  be  due  to 
fracture  or  dislocations  of  the  humerus.  Duchenne  (1867)  was  the  first  to 
appreciate  the  fact  that  the  essential  factor  in  these  injuries  was  a  nerve  lesion 
and  not  a  fracture  as  was  held  at  that  time.  He  proposed  for  these  paralyses 
the  name  of  "obstetrical  palsy,"  thus  to  stress  the  importance  of  the  nerve 
injury,  and  divided  these  into  two  tyqjes:  those  due  to  compression  and  those 
due  to  laceration. 

Following  the  work  of  Duchenne  numerous  cases  were  reported,  notably 
by  Erb  (1874)  who  presented  one  case  of  obstetrical  paralysis  and  subsequently 
published  a  series  of  identical  paralyses  in  adults.  Erb  considered  paralysis 
at  childbirth  to  be  due  to  compression  of  the  fifth  and  sixth  cer\-ical  roots  at 
the  outer  border  of  the  sternocleidomastoid  muscle  and  at  a  point  2  cm. 
above  the  clavicle.  This  point  has  subsequently  been  called  Erb's  point. 
However,  in  accounting  for  the  etiology  of  the  one  case  of  birth  palsy  which 
Erb  reported  he  attempted  to  explain  the  lesion  as  due  to  pressure  of  the  finger 


BRACHIAL   PLEXUS 


237 


in  tlie  axilla  during  the  process  of  version  and  extraction.  This  view  was  also 
held  by  Seeligniuller  (1877)  and  others.  As  Taylor  (1905)  pointed  out,  Erb's 
explanation  is  inconsistent  both  as  to  the  location  of  the  injury  and  the  effect  of 
compression  in  the  axilla  which  he  believed  essential  for  the  production  of  this 
type  of  paralysis.  The  distribution  of  the  paralysis  found  in  these  cases  could 
not  be  accounted  for  by  pressure  on  the  nerves  in  the  axilla. 


•o 


/  ♦^ — CervLCa-L  svnnp. 


Cszm 


Thi 


Fig.  90. — Schematic  drawing  sliowing  the  anatomical  basis  of  Horner's  syndrome.  The 
preganglionic  sympathetic  fibers,  a,  arise  from  cells  in  the  lateral  column  of  the  ventral  gray  of  either 
the  eighth  cervical  or  first  thoracic  segments  and  leave  the  spinal  nerves  via  the  white  ramus  com- 
municans  to  enter  the  cervical  sympathetic.  For  these  fibers  to  be  involved  the  injury  to  the  spinal 
nerve  must  be  central  to  h,  thus  very  close  to  the  vertebral  foramen. 

Thdrliurn  (1886)  considered  pressure  of  the  clavicle  on  the  plexus  as  a 
possible  etiological  factor.  Experimentally,  neither  Taylor  nor  Sever  were 
able  to  produce  the  lesion  by  this  mechanism. 

A  few  years  after  Duchenne's  report  on  obstetrical  palsies  Sceligmiiller 
(1877)  described  a  similar  lesion  involving  the  lower  roots  of  the  brachial 
plexus  which  invoh-ed  fibers  of  the  cervical  sympathetic  and  showed  among  its 
signs,  the  syndrome  of  Horner  (1869),  that  is,  narrowing  of  the  palpebral  fissure 
ptosis  and  miosis  of  the  pupil — the  result  of  paralysis  of  the  dilator  of  the  iris; 
sinking  in  of  the  eyeball — enophthalmus — due  to  paralysis  of  the  intra-orbital 


238  SURGICAL    AND    MECHANICAL    TREATMENT     OF    PERIPHERAL    NERVES 

muscle  of  Miiller.  Whenever  this  syndrome  is  present  in  brachial  plexus 
injuries  it  is  indicative  of  a  lesion  involving  the  eighth  cervical  or  first  thoracic 
root  and  is,  therefore,  an  aid  in  localization.  Such  involvement  of  the  sympa- 
thetic fibers  indicates  injury  to  the  plexus  very  close  to  the  vertebral  foraminaj 
since  the  fibers  from  the  ciliospinal  center  leave  the  spinal  cord  through  the 
eighth  cervical  or  first  thoracic  roots  and  reach  the  sympathetic  through  the 
white  rami  communicantes  which  comes  oft  the  nerve  at  the  beginning  of  the 
ventral  primary  division.  If  either  of  these  nerve  roots  are  injured  distal  to 
the  emergence  of  these  fibers  the  ciliospinal  path  is  not  disturbed.     (See  Fig.  90.) 

Etiology. — In  the  succeeding  years  following  Duchenne's  observations 
many  reports  of  obstetrical  paralysis  were  made,  but  it  was  not  until  the  experi- 
mental work  of  Fieux  (1897)  and  of  Clark,  Taylor  and  Prout  (1905)  that  a 
definite  etiological  conception  of  their  formation  was  given.  Taylor 
was  the  first  to  show  experimentally  that  overstretching  of  the  nerve  roots 
with  laceration  was  the  etiological  factor  in  the  causation  of  obstetrical  palsies. 
Previously  Ahrens  (1899),  Carter  (1892)  had  proposed  this  theory  as  a  clinical 
explanation  of  this  condition.  However,  to  the  thorough  work  of  Taylor 
credit  is  due  for  bringing  to  the  attention  of  the  surgeon  the  need  of  a  definite 
appreciation  of  the  pathological  changes  resulting  from  laceration  of  the 
nerve  roots  in  obstetrical  paralysis  and  for  outlining  a  rational  operative  and 
mechanical  treatment  of  them.  Taylor's  excellent  studies  have  shown  that 
birth  palsies  are  the  result  of  overstretching  and  rupture  of  the  component 
cervical  nerve  roots  of  the  brachial  plexus  whenever  the  head  and  shoulders 
are  forced  apart  irrespective  of  the  nature  of  the  presentation. 

J.  J.  Thomas  and  Sever  (191 6)  after  an  exhaustive  study  of  obstetrical 
paralysis  concluded  that  this  lesion  is  due  to  trauma  of  the  brachial  plexus 
during  birth,  irrespective  of  the  presentation.  Their  data  exclude  the  possi- 
bility of  such  a  lesion  being  produced  by  fracture  or  dislocation  of  the  humerus, 
separation  of  the  epiphysis,  or  injury  of  the  joint  capsule.  These  latter  patho- 
logical changes  may  also  be  met  with  in  obstetrical  paralysis,  but  they  are 
only  coincident  lesions.  Thomas  and  Sever  agree  with  Taylor  that  traction 
and  overstretching  is  the  mechanism  of  brachial  plexus  injuries  and  may  be 
the  only  method  of  producing  the  injury.  Their  statistics  show  that  of  four 
hundred  and  seventy-one  cases  studied,  two  hundred  and  thirty-five  were  in 
boys  and  two  hundred  and  thirty-six  were  in  girls;  that  the  right  arm  was 
involved  two  hundred  and  seventy-two  times,  and  the  left  arm  one  hundred 
eighty-six.     The   lesion  occurred  two  hundred  and  ninteen   times  in  vertex 


BRACHIAL   PLEXUS 


239 


Fig.  gi. — Microphotographs  of  the  third  and  seventh  cervical,  with  the  third  thoracic  and  fourth 
lumbar,  stained  by  Weigert-Pal.  Sections  show  cord  changes  in  a  case  of  birth  palsy.  The  seventh 
cervical  is  the  level  of  the  maximum  change.  The  right  side  of  the  cord  is  small  and  flattened  ven- 
trally.  The  fibrosis  is  marked  and  infiltrates  the  peripheral  part  of  the  cord  over  nearly  its  whole 
circumference.     (Boyer,  Proc.  Roy.  Soc.  of  Medicine.) 


240        SURGICAL   AND   MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 

presentations,  sixty-six  times  in  breech,  and  in  one  hundred  and  eighty-live 
the  presentation  was  not  recorded.  In  four  hundred  and  nineteen  the  labor  was 
long  and  laborious;  in  three  hundred  and  seventeen  forceps  were  used,  and  in 
thirty-two  labor  was  apparently  normal.  The  Duchenne-Erb  type  was  found  in 
four  hundred,  and  in  eighty-four  the  lower  roots  were  involved  as  well.  In  nine 
cases  both  arms  were  affected,  and  in  each  the  lesion  involved  the  component  roots 
of  the  brachial  plexus  from  the  fifth  cervical  to  the  first  thoracic,  inclusive. 

Rupture  of  the  nerve  roots  occurs  first  in  those  roots  under  the  greatest 
stress;  the  stress  is  greatest  on  the  fifth,  sixth,  seventh  and  eighth  cer\'ical  in 
the  order  named.  The  fifth  cervical  arises  highest  from  the  cer\ical  spine  and, 
therefore,  is  stretched  the  most  when  the  head  and  shoulder  are  forced  apart  and 
hence  is  the  first  to  give  away. 

Location  of  the  Injury  to  the  Nerve  Roots. — The  most  frequent  location 
of  injury  to  the  bracliial  plexus  in  obstetrical  palsy  is  at  the  junction  of  the  fifth 
and  sixth  cervical  roots  at  about  the  point  at  which  the  suprascapular  nerve 
is  given  ofi".  In  infants  the  fifth  and  sixth  cervical  roots  extend  approximately 
2  to  2  3^^  cm.  from  the  intervertebral  foramina  and  the  combined  primary  trunk 
is  approximately  i  cm.  long. 

Clark,  Taylor  and  Prout  found  in  twenty  experiments  in  whicli  the  head 
and  shoulder  were  forced  apart  that  the  lesion  was  as  follows: 

Fifth  Nerve  Sixth  Nerve 

Above  junction 16-80  %  17-85% 

At  junction 2-10%  2-10% 

Below  junction 2-10%  1-5% 

"In  seven  experiments  (35%)  the  sixth  cervical  root  was  evulsed  from  the 
spinal  cord  including  the  root  ganglion." 

Secondary  Injury  to  the  Spinal  Cord. — Boyer  (191 1)  made  a  complete 
neuropathological  examination  of  a  case  of  birth  palsy  in  which  the  seventh 
cervical  root  was  ruptured  in  the  posterior  triangle  of  the  neck  and  also 
evulsed  from  the  spinal  cord.  His  findings  are  extremely  interesting.  The 
seventh  cervical  segment  showed  that  "the  right  side  of  the  cord  is  small  and 
flattened  anteriorly.  The  fibrosis  is  marked  and  infiltrates  the  peripheral  part 
of  the  cord  for  nearly  its  whole  circumference.  (See  Fig.  91.)  The  anterior 
horn  zone  is  so  involved  in  its  sclerosis  that  it  lies  bare  upon  the  anterolateral 
surface  of  the  cord.  The  gray  matter  of  both  sides  is  very  distorted  and  the 
cells  are  entirely  absent  on  the  right  side  and  only  a  few  darkly  stained  elongated 
forms  remain  on  the  left."  This  level  marks  the  maximum  change  in  the  cervical 
cord,  the  severity  of  the  lesion  gradually  diminishing  both  above  and  below. 


BRACHIAL    PLEXUS 


241 


Changes  were  also  noted  in  the  meninges  in  the  region  of  the  fifth,  sixth, 
seventh  cervical  and  first  thoracic  segments.  At  these  levels  the  meninges 
were  dense,  tough  and  thickened,  and  adherent  to  the  cord  on  the  right  side 


Fig.  92. — Transverse  section  through  cords  of  left  brachial  plexus.     Microphotograph  of  Weigert 
Pal  stained  section.     (Boyer,  Proc.  Roy.  Soc.  of  iVIedicine.) 


Fig.  92a. — Transverse  section  through  cords  of  right  brachial  plexus.  This  is  the  side  of 
the  paralj'sis.  Microphotograph  of  Weigert-Pal  stained  section.  (Boyer,  Proc.  Roy.  Soc.  of 
Medicine.) 

though  extending  somewhat  also  onto  the  left.  Likewise  the  area  of  greatest 
thickening  was  at  the  level  of  the  seventh  cervical  segment  and  diminished 
both  above  and  below  this  point.  The  ventral  roots  from  these  segments  were 
reduced  to  fibrous  cords  and  the  Ijrachial  plexus  was  smaller  on  the  affected 
side  and  the  nerve  trunks  were  bound  down  by  tough  fibrous  tissues.  (See 
Fig.  92-92?/). 


242 


SURGICAL    AND    MECHANICAL    TREATMENT   OF    PERIPHERAL    N^ERVES 


This  case  is  specially  noteworthy  because  of  rupture  of  the  plexus  in  the 
posterior  triangle  of  the  neck,  on  account  of  the  damage  done  to  the  roots  arising 
from  the  cord  as  ivell  as  the  injury  to  the  cord  itself.  Thus  if  the  plexus  had 
been  operated,  no  improvement  would  have  been  possible.  It  is  probable  that 
injuries  of  this  type  are  more  common  and  unrecognized,  thus  accounting  for 
some  of  the  unfavorable  results  seen  in  obstetrical  paralyses. 

Somewhat  similar  cord  changes  were  described  by  Philippe  and  Cestan 
(1900)  in  which  more  dorsal  roots  were  involved  than  ventral  with  extensive 
spinal  cord  changes.  Burr  (1892),  Neurath(igoi)  are  also  of  the  opinion  that  in- 
juries to  the  cord  in  birth  palsies  are  more  common  than  is  generally  credited.  A 
careful  search  should  be  made  for  spinal  symptoms.     I  have  seen  evidence  of 


luntr  Co'd,  (Cg  A  Oi  j 

6rJfC/t  fe  /bsA  fert/  frttm  IC^  i  ^if. 

Branth  to  fosl.  card  from  (C/;  i  O,} 

araHth  to  Pcif  lord  from  f^^j 


V^^rO 


Fig.  926. — Key  to  Figs.  92  and  92a. 


spinal  cord  invol\"emcnt  in  two  patients  in  one  ten  and  in  the  other  nineteen 
years  after  birth.  In  both  a  small  triangle  of  anesthesia  could  be  outlined 
corresponding  to  the  distribution  of  the  fifth  and  sixth  cervical  nerves  on  the 
back  within  the  area  included  between  the  parieto-mastoid-trochanter  coccygeal 
lines.  Anesthesia  in  this  area  at  once  places  the  lesion  central  to  the  primary 
dorsal  divisions  of  the  fifth  and  sixth  cervical  nerves.  (See  p.  228.)  The  knee, 
ankle  and  hamstring  jerks  were  increased,  and  the  abdominal  reflexes  diminished 
on  the  side  of  the  injury.  Babinski  was  present  in  only  one  of  the  patients. 
No  evidence  of  spinothalamic  or  dorsal  column  changes  were  made  out. 

Pathology. — As  has  already  been  indicated  the  nature  of  the  lesion  in 
laceration  of  the  brachial  plexus  differs  materially  from  that  seen  in  incised  or 
gunshot  wounds,  in  that  in  the  former  the  extent  of  the  lesion  is  irregular,  the 
funiculi  are  pulled  apart  at  different  levels,  some  ruptured  within  the  central 
and  others  within  the  distal  stump.     (See  Figs.  93,  94  and  95.) 


BRACHIAL    PLEXUS 


243 


Fig.  93. — Schematic  drawing  of  the  brachial  plexus  seen  from  behind.  The  spinous  processes 
and  lamina  have  been  removed  and  the  dura  opened,  exposing  the  spinal  cord  and  the  nerve  roots. 
The  lines  within  the  nerve  roots  and  the  trunks  of  the  plexus  represent  funiculi,  the  dotted  line  the 
clavicle. 


Fig.  94. — Schematic  drawing  of  the  brachial  plexus  seen  from  behind  as  in  Fig.  03  to  illustrate 
the  mechanism  of  brachial  plexus  injuries  at  birth.  The  right  shoulder  is  lowered  and  the  head  bent 
lo  the  opposite  side,  thus  increasing  the  acromiomastoid  distance.  The  former  position  of  the 
shoulder  is  indicated  by  dotted  lines.  The  fifth,  sixth  and  seventh  cervical  roots  are  torn,  the  fifth 
and  sixth  at  their  junction.  Xote  that  the  rupture  is  irregular,  the  ends  frayed  and  the  funiculi 
torn  at  .v  both  central  and  distal.     Insert  indicates  the  ends  prepared  for  suture  and  sutures  in  place. 


244         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Considered  from  a  histological  standpoint  these  pathological  differences 
between  lacerated  and  incised  wounds  of  the  nerve  trunk  limit  the  possibilities 
of  successful  surgical  interference.  When  the  funicuh  are  torn,  rupture  of  the 
neuraxes,  blood  vessels  and  the  connective  tissue  sheath  takes  place,  within  the 
nerve  trunk  so  that  small  multiple  hemorrhages  occur  in  and  around  the 
funiculi  which  lead  to  scar  formation  and  eventually  to  contraction  about  the 
funiculi  or  interposition  of  scar  between  the  ends  of  the  funiculi,  thus  preventing 
regeneration.     Judging  from  the  appearance  of  the  cross  section  at  any  given 


Fig.  g5. — Schematic  drawing  of  the  brachial  plexus  seen  from  behind  as  in  Fig.  g4.  The  in- 
crease in  the  acroraioraastoid  distance  is  greater  and  the  injury  to  the  plexus  more  extensive.  The 
fifth,  sixth,  and  seventh  roots  are  completely  evulsed  from  the  spinal  cord,  the  eighth  is  torn  within 
the  intervertebral  foramen  and  in  the  lirst  thoracic  the  continuity  of  the  sheath  is  maintained  while 
the  funiculi  within  are  torn.  In  this  case  complete  paralysis  of  the  extremity  w-ould  occur  and 
Horner's  syndrome  would  be  found.  Insert  shows  evulsion  of  the  ventral  and  dorsal  roots  from  the 
cord,  with  the  axon  of  the  motor  ventral  gray  cell  and  the  central  process  of  the  spinal  ganglion 
interrupted. 

level  it  is  not  possible  to  determine  whether  the  funiculi  seen  are  intact  centrally 
or  evulsed  from  the  cord  or,  perhaps,  even  interrupted  peripherally.  In  severe 
forms  the  deep  cer\'ical  fascia  is  also  torn  and  the  fascia  may  become  adherent 
to  the  nerve  roots  or  interposed  between  the  nerve  cords. 

If  wide  excision  is  made  in  an  attempt  to  insure  sound  funiculi  both  proxi- 
mally  and  distally  important  nerve  branches  arising  from  the  plexus  may  be 
endangered  and  approximation  be  impossible.  In  selected  cases  nerve  graft 
may  be  indicated.      An  autogenous  graft  is  not  feasible  due   to  the   small 


BRACHIAL    PLEXUS  245 

length  and  diameter  of  the  skin  nerves  in  the  infant,  to  the  general  contrain- 
dications of  an  additional  wound  and  on  account  of  the  length  of  time 
involved.  Consequently  preserved  grafts  should  be  used  if  a  graft  is  to  be 
clone,  yet  even  with  these  the  operation  requires  considerable  time  providing 
the  suture  is  accurately  done.  Always  every  attempt  should  be  made  to 
obtain  end-to-end  union.  Thus,  considering  the  pathology  of  the  lesion  and  the 
histology  of  nerve  regeneration,  obstetrical  paralyses  offer,  perhaps,  the  least 
opportunity  for  successful  nerve  surgery. 

Mechanical  Treatment.  Deformity. — This  has  already  been  described  in 
describing  the  different  types  of  brachial  plexus  injuries.  The  treatment  of 
obstetrical  paralyses  is,  first,  immediate  immobilization  so  as  to  prevent  addi- 
tional hemorrhage  and  further  separation  of  the  nerve  ends  due  to  movement 
and  the  unsupported  weight  of  the  extremity.  As  soon  after  birth  as  the 
paralysis  is  recognized  the  arm  should  be  placed  in  a  sling  or  the  sleeve  pinned 
up  to  a  cap  and  a  small  pad  strapped  in  the  axilla  to  raise  the  shoulder,  thus 
preventing  the  arm  from  dragging  down  the  shoulder  and  further  separating 
the  nerve  ends.  This  position  should  be  held  until  the  child  is  two  or  three 
weeks  old,  when  a  splint  may  be  applied. 

Any  of  the  splints  similar  to  those  shown  in  Figs.  88  and  Sg  are  suitable. 
They  should  be  made  of  very  light  material,  preferably  aluminum  or  hght 
plaster,  and  readily  removable.  The  arm  should  be  elevated  in  abduction 
beyond  90°  in  order  to  relax  the  deltoid,  and  to  assist  in  bringing  the  shoulder 
nearer  to  the  neck,  thus  lessening  the  distance  between  the  torn  nerve  ends. 
After  operation  if  desired  this  angle  may  be  increased  and  the  arm  held  nearly 
vertical.  Thus  i  to  2  cm.  additional  may  be  gained  over  that  obtained  when  the 
arm  is  held  abducted  at  90.°  The  forearm  is  semiflexed  upon  the  arm  to  relax 
the  biceps  and  supinator  longus.  The  hand  should  be  turned  in  full  supination 
to  overcome  the  tendency  to  pronation  and  the  extremity  must  be  held 
in  external  rotation. 

This  splinting  should  of  course  be  combined  with  passive  movements  and 
exercises  to  overcome  any  tendency  to  fixation  and  to  help  increase  the  nutri- 
tion of  the  part.   To  this  end  massage,  bathing  and  electricity  should  also  be  used. 

Duration  of  Treatment. — If  the  case  has  been  treated  in  this  manner 
for  a  year  without  improvement  it  is  probable  that  regeneration  without 
operation  will  not  take  place.  On  the  other  hand,  if  signs  of  regeneration  are 
found  the  mechanical  treatment  should  be  continued  and  no  operation  under- 
taken unless  there  are  evidences  of  interru[)ted  regeneration.     In  an  infant, 


246         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

the  sensory  examination  is  of  relatively  little  value  as  an  indication  of  regenera- 
tion so  that  we  must  rely  upon  the  motor  and  electrical  findings  together  with 
the  appearance  of  the  extremity  with  its  indications  of  alterations  in  the 
vasomotor  and  trophic  status.     (See  p.  164.) 

Late  Mechanical  Treatment. — If  the  case  has  been  untreated  mechanically 
no  operation  should  be  undertaken  until  the  muscles  have  been  put  at  complete 
rest  and  further  overstretching  prevented.  Even  when  cases  have  been 
neglected  four  or  five  years  or  longer  mechanical  treatment  alone  may  give 
marked  improvement  and  lead  to  establishment  of  contractility  in  the  paralyzed 
muscles.  Clinical  experience  in  birth  palsies  has  shown  that  muscles  which 
are  overstretched  do  not  regain  their  contractility,  even  though  neurotization 
has  apparently  taken  place  until  they  have  been  placed  at  rest  and  over- 
stretching prevented  for  at  least  six  months.  (See  Chapter  IX.)  Boorstein 
(1919)  has  demonstrated  the  advantages  of  adequate  mechanical  treatment  of 
brachial  plexus  injuries  and  has  recommended  the  exercises  advocated  by 
Sweeney  (1913),  Thomas  (1914),  Bucholz  (1917),  which  tend  to  prevent  con- 
tractures and  to  assist  in  re-education  when  regeneration  has  occurred.  These 
exercises  are  as  follows: 

((/)  Under  the  age  of  two  months  one  uses  gentle,  irregular  movements, 
carried  out  by  the  operator,  and  by  the  mother  between  treatments,  such  as 
moving  the  baby's  hand  and  arm  in  various  directions,  in  imitation  of  voluntary 
movements  made  by  the  other  arm. 

{h)  After  two  months  it  is  advisable  to  bend,  stretch  or  spread  the  baby's 
fingers  while  using  the  operator's  arm  in  a  similar  way.  It  is  best  to  accompany 
this  by  a  nursery  rhyme  and  the  child  will  begin  to  imitate  that.  The  hand 
should  be  flexed  and  extended  at  the  wrist  and  then  carried  to  the  neck,  thus 
flexing  the  forearm.  The  forearm  should  be  abducted,  adducted  with  the 
hand  supinated  and  the  elbow  bent  and  held  at  the  side;  arm  extension  in 
supination  where,  with  the  elbow  bent  and  at  the  side  of  the  forearm,  it  should 
be  rotated  outward,  but  within  the  limits  of  comfort;  the  hand  in  supination, 
the  arm  should  be  extended]  by  the  operator  in  the  direction  of  the  line  of  the 
forearm. 

The  arm  should  be  lifted  to  as  near  a  vertical  position  as  possible,  from  a 
position  of  extension  in  supination;  then  from  the  vertical  position  the  elbow 
should  be  lowered  to  the  side  bringing  the  hand  to  the  shoulder  or  neck.  From 
the  position  with  the  elbow  bent  and  at  the  side  the  arm  should  be  stretched 
out  and  returned,  and  the  arm  in  the  horizontally  stretched  out  position  should 


BRACHIAL    PLEXUS  247 

be  swung  to  describe  a  curve.  These  exercises  are  to  be  repeated  two  to  eight 
times  each. 

Both  arms  slioukl  be  stretched  sideways  three  or  four  times  and  then  the 
hands  carried  to  the  head;  the  arms  should  be  extended  upward,  and  then 
returned  to  the  bent  position;  the  arms  form  a  circle  in  front  of  the  body,  the 
lingers  touching,  and  then  the  arms  should  be  carried  upward  until  the  hands 
are  over  the  head  and  then  separated  and  lowered  to  the  sides.  For  a  part  of 
each  day  the  healthy  arm  should  be  bandaged  to  the  body,  thus  forcing  the 
baby  to  use  his  affected  arm  as  much  as  possible. 

At  the  age  of  ten  or  twelve  months  it  is  appropriate  to  use  blocks  and  per- 
haps put  the  blocks  in  dilTerent  places  and  make  the  child  reach  for  them.  One 
may  also  induce  the  child  to  put  blocks  in  a  box  held  at  different  places. 

At  the  age  of  eighteen  months  the  child  can  perform  in  the  first  group  of 
exercises  voluntarily,  and  dumb-bells,  wands,  balls,  bean-bags  and  such  things 
could  be  used. 

At  two  and  a  half  or  three  years,  the  child  will  swing  on  a  bar,  walk  into 
a  corner  with  arms  spread  out,  creep  up  the  wall. 

The  last  muscles  to  develop  are  usually  the  outward  rotators  of  the  humerus 
and  supinators.  One  may  use  the  following  exercise:  With  the  elbow  bent 
at  the  side,  and  the  forearm  in  supination  and  abduction,  with  a  small  iron 
dumb-bell  in  the  hand,  the  arm  is  extended  in  the  direction  of  the  line  of  the 
forearm. 

The  following  exercises  for  older  children  may  be  used: 

(i)   Wing  standing;  chest  raising  with  deep  breathing. 

Position:  Standing  erect. 

Exercise:  Forcible  chest  elevation  with  deep  breathing. 

(2)  On  table  on  back,  stick  raising  with  deep  breathing. 
Position:  On  table  on  back,  hands  well  separated,  grasping  stick. 
Exercise:  Stick  raising  over  head  with  inhalation,  sinking  with  exhalation. 

(3)  Rest  sitting,  chest  expansion. 

Position:  Sitting  on  bench,  hands  behind  head,  elbows  well  back,  careful 
not  to  hollow  back  during  exercise;  support  should  be  given  by  operator. 

Exercise:  At  inhalation  the  arms  are  lifted  up  and  back  and  returnetl  to 
starting  position  on  exhalation.  Good  pull  should  be  given  to  gain  the  desired 
pectoral  stretch. 

Cane  exercises:  Cane  held  in  both  hands. 

(i)  Raise  cane  with  arms  straight. 


248         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

(2)  Flex  the  elbow  and  lift  the  cane  up  in  front  of  the  chest;  from  this 
position  the  cane  is  brought  forward  or  upward  or  to  any  angle  desired. 

(3)  One  end  of  the  cane  is  raised  up  to  one  side  of  the  body,  while  the 
other  is  placed  on  the  other  side. 

(4)  The  cane  is  held  in  front  of  the  chin  with  the  hands  about  3  feet 
apart;  then  it  is  moved  horizontally  toward  one  side  and  then  the  other.  This 
exercise  can  also  be  done  with  the  cane  on  the  back  of  the  neck. 

(5)  The  cane  is  held  on  the  back,  then  the  affected  arm  is  raised  up  as  high 
as  possible,  and  the  patient  has  to  bring  scapula,  elbow  and  wrist  as  much  as 
possible  in  a  straight  line,  pressing  these  three  points  against  the  cane. 

In  this  exercise  the  affected  arm  extends  actively,  the  other  hand  pushes 
passively,  and  both  together  force  the  shoulder  and  the  elbow  in  a  straight 
line. 

Time  of  Operation. — Due  to  the  peculiar  pathology  of  these  injuries  it  is 
often  extremely  difficult  at  operation  to  determine  the  extent  of  the  damage 
done,  since  some  of  the  gross  changes  may  not  be  apparent  such  as  intraneural 
rupture  of  funiculi,  centrally  or  distally,  or  evulsion  within  the  intervertebral 
foramina.  Hence,  immediate  or  early  radical  operative  procedures  seem 
hardly  justified  in  view  of  the  large  percentage  that  recover  within  a  year 
without  operation,  if  properly  treated  mechanically.  By  early  operation 
it  is  often  impossible  to  distinguish  those  that  will  go  on  to  regeneration  from 
those  that  will  not.  Spontaneous  regeneration  can  hardly  be  expected  under 
six  months  or  a  year  and  surgical  intervention  should  not  be  undertaken 
until  the  end  of  this  period.  If  the  patient  is  properly  treated  mechanic- 
ally such  delay  is  permissible.  Taylor  prefers  to  operate  at  the  end  of  three 
months  if  there  are  no  signs  of  regeneration,  while  Sharpe  (1916)  operates 
at  the  end  of  a  month.  Very  few  patients  will  show  signs  of  regeneration 
within  a  month  so  that  this  latter  view,  practically,  would  mean  operating 
every  case — a  view  rarely  held.  When  older  the  operative  field  is  larger  and 
the  patient  is  better  able  to  withstand  the  operation.  In  considering  explora- 
tion the  proximity  of  the  great  vessels  and  possible  severe  hemorrhage  in  an 
infant  must  always  be  borne  in  mind.  The  author  believes  that  the  great 
difference  in  the  pathology  of  these  injuries  as  compared  with  other  nerve 
injuries  and  the  extreme  youth  of  the  individual  warrants  that  a  year  be  waited, 
providing  continuous  mechanical  treatment  is  given. 

The  power  of  the  nerve  fiber  to  regenerate  is  infinitely  greater  in  the  infant 
than  in  later  life  and  young  developing  muscles  are  less  apt  to  undergo  regressive 


BRACHIAL    PLEXUS  249 

changes  of  a  permanent  character.  If  regeneration  has  not  taken  place  within 
a  year,  delay  longer  is  not  warranted  in  patients  that  have  been  properly  treated 
by  splints,  massage  and  passive  movements. 

On  the  other  hand,  the  nature  of  the  injury  may  be  such  that  operation 
can  accomplish  little  or  nothing.  Obviously  where  the  nerve  roots  are  evulsed 
nothing  can  be  done,  but  in  favorable  cases  in  which  the  anatomical  continuity 
of  the  nerve  trunks  can  be  re-established  operative  intervention  is  certainly 
justifiable  and  offers  the  best  opportunity  for  regeneration  and  return  of 
function.  In  some  instances  when  several  nerve  roots  are  evulsed  or  injured 
so  that  end-to-end  suture  cannot  be  done  they  may  be  crossed  to  adjacent 
roots. 

Operation. — The  technic  elaborated  by  Taylor  is  most  satisfactory. 

"The  patient  is  anesthetized  and  brought  to  the  table  with  the  field  pre- 
pared for  operation.  A  firm  cushion  is  placed  beneath  the  shoulders,  the  neck 
is  moderately  extended  and  the  face  turned  to  the  sound  side.  The  incision 
passes  from  the  posterior  border  of  the  sternomastoid  muscle,  at  the  junction 
of  its  middle  and  lower  thirds,  downward  and  outward  to  the  clavicle  at  the 
junction  of  its  middle  and  outer  thirds.  After  the  skin,  platysma  and  deep 
fascia  are  divided,  the  omohyoid  muscle  is  exposed  near  the  clavicle,  and  lying 
beneath  it  are  the  suprascapular  vessels.  These  structures  may  be  retracted 
downward,  or,  if  the  case  requires  the  extra  room,  the  omohyoid  maybe  divided, 
and  then  the  vessels  cut  between  double  ligatures.  The  transversalis  colli 
vessels  are  seen  a  little  below  the  middle  of  the  wound  and  are  divided  between 
doul)le  ligatures. 

■'The  dissection  is  rapidly  carried  through  the  fat  layer  to  the  deep  cervical 
fascia  covering  the  brachial  plexus.  In  all  the  cases,  this  fascia  was  thickened 
and  adherent  to  the  damaged  nerve  roots.  This  fascia  is  divided  in  the  line  of 
the  original  incision  and  is  dissected  away  for  the  free  exposure  of  the  nerves. 
The  damaged  nerves  are  usually  noticeably  thickened  and  of  greater  den- 
sity than  normal  nerves.  The  extent  and  distribution  of  the  paralysis,  deter- 
mined before  operation,  gives  the  clue  as  to  which  nerves  are  at  fault.  Usually 
the  junction  of  the  fifth  and  sixth  roots  is  the  site  of  maximum  damage.  The 
thickened  indurated  areas  are  determined  by  palpation  and  are  excised  by 
means  of  a  sharp  scalpel.     Scissors  should  never  be  used  for  this  work. 

"The  nerve  ends  are  brought  into  apposition  by  lateral  sutures  of  fine  silk 
involving  the  nerve  sheaths  only,  while  the  neck  and  shoulder  are  approximated 
to  prevent  tension  on  the  sutures.     Cargile  membrane  is  wrapped  about  the 


250         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

anastomosis  to  prevent  connective  tissue  ingrowth.  The  omohyoid  muscle,  if 
divided,  is  sutured.  The  wound  is  closed  with  silk.  A  firm  sterile  dressing  is 
applied,  and  a  bandage  is  applied  to  approximate  head  and  shoulder  so  as  to 
prevent  tension  on  the  nerve  sutures.  This  position  must  be  maintained  for  at 
least  three  weeks.  The  most  feasible  method  of  accomplishing  this  result  was 
found  to  be  a  plaster-of-paris  dressing  placed  on  the  child  and  allowed  to  harden 
in  the  proper  position  before  operation.  It  was  then  trimmed  and  removed. 
When  the  nerve  suturing  was  finished  the  splint  was  slipped  on,  the  wound  was 
then  closed,  the  dressings  applied,  and  the  child  put  to  bed  without  danger  of 
pulling  the  nerve  ends  apart,  even  when  the  patient  was  struggling  and  ^•omiting 
in  the  recovery  from  anesthesia. 

"It  will  be  noticed  that  (a)  the  tissues  to  be  excised  lie  in  close  proximity  to 
the  phrenic  nerve  and  internal  jugular  vein,  and  to  the  junction  of  the  cervical 
sympathetic  communications  with  the  spinal  nerve  roots,  {b)  The  supra- 
scapular nerve  comes  off  from  the  junction  of  the  fifth  and  sixth  cervical  nerve 
roots,  which,  as  already  stated,  is  usually  the  site  of  maximum  damage.  This 
nerve  is  very  small  in  children,  but  it  should  be  sutured  with  the  greatest  care, 
since  it  innervates  the  external  rotators  of  the  humerus,  the  paralysis  of  which 
permits  the  posterior  dislocation  of  the  shoulder  often  seen  in  the  older  cases. 

"in  cases  in  which  the  lesion  is  more  extensive,  especially  when  it  lies 
beneath  the  clavicle,  a  wider  exposure  is  necessary  (Fig.  97).  It  is  obtained  by 
continuing  the  skin  incision  downward  between  the  pectoralis  major  and  deltoid 
muscles,  which  are  then  separated,  dividing  the  clavicle  in  the  same  line,  as  well 
as  the  subclavius  and  omohyoid  muscles  and  suprascapular  vessels. 

"When  the  outer  fragment  of  the  clavicle  and  the  shoulder  are  pulled  out- 
ward the  entire  plexus  is  exposed  down  to  the  upper  margin  of  the  pectoralis 
minor  muscle,  which  may  also  be  divided  if  necessary.  When  the  nerve  suture  is 
completed  the  divided  muscles  are  repaired,  the  clavicle  is  sutured  with  chromic 
gutj  and  the  skin  closed  with  silk.  In  certain  cases  of  extensive  damage,  in 
which  so  much  nerve  must  be  excised  that  the  ends  cannot  be  brought  together, 
a  nerve  bridge  of  chromic  catgut  loops  passed  through  the  nerve  ends  and 
surrounded  by  cargile  membrane  may  be  used. 

"in  other  cases  in  which  the  cicatricial  tissue  reaches  practically  to  the 
intervertebral  foramen  and  its  complete  excision  would  not  leave  sufficient  nerve 
stump  to  pass  sutures  through,  the  root  may  be  divided  transversely  through 
cicatricial  tissue  a  short  distance  outside  the  foramen  and  then  the  stump  split 
longitudinally  upward  until  good  nerve  tissue  is  exposed.     The  distal  stump  is 


BRACHIAL    PLEXUS  25  I 

then  sutured  up  into  this  cleft,  antl  at  least  some  return  of  power  may  be 
expected." 

Surgical  Treatment  in  Neglected  Cases.- — In  cases  which  have  not  received 
mechanical  treatment — massage  and  exercise  to  prevent  contractures — there  is 
marked  limitation  in  external  rotation  and  abduction  of  the  humerus.  Even 
after  spontaneous  regeneration  such  limitation  may  persist  due  to  adaptive 
shortening  of  the  subscapularis  and  the  sternal  portion  of  the  pectoralis  major. 
The  contracted  subscapularis  which  normally  rotates  the  arm  inward  prevents 
external  rotation  and  in  more  severe  cases  also  hmits  abduction.  The  latter 
movement  is  prevented  more  particularly  by  contracture  of  the  sternal  por- 
tion of  the  pectoralis  major. 

When  these  contractures  cannot  be  overcome  by  splinting  and  exercises 
tenotomy  of  the  subscapularis  and  the  sternal  portion  of  the  pectoralis  major  is 
indicated.  In  neglected  cases  without  regeneration,  tenotomy  of  these  muscles 
may  be  done  at  the  same  time  that  repair  of  the  nerve  injury  is  undertaken. 
The  operation  as  recommended  by  Thomas  and  Sever  is  as  follows: 

"An  incision  is  made  situated  on  the  anterior  aspect  of  the  arm  and  extend- 
ing from  the  clavico-acromial  joint  to  a  point  below  the  lower  edge  of  the  pecto- 
ralis major  tendon.  The  incision  is  carried  down  between  the  deltoid  and 
clavicular  portions  of  the  pectoralis  major  tying  or  retracting  the  cephalic 
vein.  The  tendon  of  the  pectoralis  major  is  isolated  and  divided  on  a  director. 
Turning  the  cut  pectoralis  major  back  and  retracting  the  deltoideus  gives  a 
good  view  of  the  long  head  of  the  biceps  and  the  joint  capsule,  short  head 
of  the  biceps  as  well  as  the  coracobrachialis.  The  arm  is  now  abducted  and 
outwardly  rotated,  bringing  into  \iew  the  transverse  libers  of  the  tendon 
of  the  subscapularis  at  its  point  of  insertion  into  the  joint  capsule  at  its  inner 
and  anterior  aspect.  This  tendon  is  isolated  and  a  sound  or  other  blunt 
instrument  is  passed  under  it,  and  it  is  then  divided.  In  this  way  not  only  is  the 
pectoral  divided,  which,  when  contracted,  prevents  abduction,  but  also  the  sub- 
scapularis is  divided,  which,  when  contracted,  prevents  outward  rotation.  It  is 
better  to  divide  the  subscapularis  by  this  method  rather  than  to  open  the 
joint  capsule  after  Fairbank's  method,  for  it  does  not  lead  to  subsequent  adhe- 
sion of  the  capsule  to  the  joint  cartilage  and  consequent  loss  of  motion. 

".\fter  these  two  structures  have  been  cut,  outward  rotation  and  abduction 
will  usually  be  found  to  be  perfectly  free.  In  case  either  is  at  all  restricted, 
the  coracobrachialis  or  the  short  head  of  the  biceps  may  be  found  to  be  tight, 
and  partial   dix'ision   of   these  structures  will   always  lead  to  full  freedom  in 


252         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL   NERVES 

outward  rotation  and  abduction.  If  the  head  of  the  humerus  is  blocked  by 
the  hooking  downward  of  the  acromion  in  front  of  it,  so  that  the  posterior 
subluxation  cannot  be  fully  reduced,  an  osteotomy  can  be  easily  done  on  the 
acromion  through  the  upper  end  of  the  original  incision. 

"If  there  is  an  anterior  subluxation  of  the  joint,  which  occurs  rarely, 
the  pectoralis  major  is  the  only  muscle  which  needs  to  be  divided.  A  division 
of  the  subscapularis  would  only  tend  to  increase  a  deformity  already  present. 
The  pectoralis  major  and  deltoideus  are  then  joined  with  interrupted  catgut 
sutures,  and  the  skin  closed  by  a  continuous  catgut  suture.  The  arm  is  then 
put  into  a  plaster  cast  extending  from  the  crest  of  the  ileum  to  the  tips  of  the 
fingers,  the  arm  being  abducted,  elevated,  outwardly  rotated  and  the  hand 
supinated.  This  cast  should  be  worn  only  about  two  weeks,  at  the  end  of 
which  time  baking,  massage  and  exercises  should  be  started  and  continued 
daily  for  several  months.  After  two  or  three  weeks  a  wire  splint  may  be  sub- 
stituted for  the  cast,  in  that  it  is  lighter  and  more  comfortable." 

BRACHIAL   PLEXUS   INJURIES   IN   ADULTS 

Ruptures  of  the  bracliial  plexus  in  adults,  as  has  already  been  said,  differ 
very  little  from  those  in  birth  palsies.  They  likewise  are  produced  by  any 
trauma  in  which  the  head  and  shoulder  are  forced  apart  and  the  acromio- 
mastoid  distance  lengthened,  such  as  by  a  sudden  blow  upon  the  shoulder  or 
by  a  fall  on  the  head  and  shoulder.  In  two  cases  of  rupture  of  the  brachial 
plexus  one,  a  boy  of  six,  fell  off  a  high  chair  landing  on  the  right  side  of  his 
head  and  right  shoulder;  and  the  second,  a  laborer,  was  struck  on  the  shoulder 
by  a  heavy  stone  which  fell  as  it  was  being  raised.  The  stone  struck  a  glancing 
blow  on  the  shoulder  and  immediate  paralysis  in  the  distribution  of  the  fifth, 
sixth  and  seventh  cer\-ical  roots  resulted.  Thus  in  both  of  these  the  acromic 
mastoid  distance  was  forcibly  increased. 

Taylor  and  Casamajor  (1913)  reported  six  cases  of  rupture  of  the  bracliial 
plexus  in  adults  in  each  of  which  the  mechanism  was  the  same,  namely,  trauma 
which  forced  the  head  and  shoulder  apart.  One  of  their  patients  fell  from  a 
freight  car;  another  was  caught  in  a  door  being  closed  by  hydraulic  pressure, 
and  a  third  was  struck  on  the  shoulder  by  a  hea\y  chain  which  had  fallen  from 
the  second  story.  Mills  (191 1)  has  described  a  unique  case  of  rupture  of  the 
brachial  plexus.  His  patient  was  hit  on  the  shoulder  as  he  was  walking  on 
the  sidewalk  by  the  body  of  another  man  who  had  fallen  from  a  third  story 
window.     The  left  upper  extremity  was  immediately  paralyzed  and  Horner's 


BRACHIAL    PLEXUS 


2S3 


5terno-cleiclo-mJ.^tci\dl1 

■■    ,-5c,6c,7c,8c,lD. 

Scailenul)   raed.  M. 
V'  1101-16  tVior.  N. 


6ut>clavii>n  V. 


Supra'bcajpuUr  V-A-        Supra bcavPulavN. 


Ftc.  96. — Kxiiosure  uf  Ihe  biiithiiil  |)1l'.\us  above  the  clavicle  for  stab  wound  ot  the  h/th  and  sixth 

cervical  roots. 


254         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

syndrome  was  present.  Frazier  found  that  the  ventral  and  dorsal  roots  of 
the  tifth,  sixth,  seventh,  eighth  cervical  and  first  thoracic  nerves  were  com- 
pletely evulsed  from  the  cord.  Such  sudden  and  extensive  trauma  caused 
hemorrhage  in  the  cord  and  cord  signs,  including  patellar  clonus,  ankle  clousn, 
and  Babinski  on  the  same  side  of  the  injury. 


.^^ 


iL 


\ 


U 


Fig.  g7. — Operation  for  relief  of  brachial  paralysis.  A,  Phrenic  nerve;  B,  scalenus  anticus 
muscle;  C,  internal  jugular  vein;  D,  transversalis  colli  artery;  E,  omohyoid  muscle;  F,  suprascapular 
artery;  G,  eighth  cervical  and  first  dorsal  roots;  H,  muscular  branch;  /,  subclavian  vein;  /,  hfth 
root;  K,  sixth  root;  L,  scalenus  medius  muscle;  M,  nerve  to  subclavian  muscle;  i\",  suprascapular 
nerve;  O,  transversalis  colli  artery;  omohyoid  muscle;  R,  suprascapular  artery;  5,  clavicle  and 
subclavius  muscle;  T,  pectoralis  major,  pectoralis  minor  and  deltoid  muscles;  V .  anterior  thoracic 
nerve.     (Taylor,  J.  A.  M.  A.,  1907.) 

In  adults  the  trauma  is  generally  more  severe,  consequently  the  nerve 
trunks  are  more  often  ruptured  and  the  ends  pulled  completely  apart.  A 
search  for  signs  of  spinal  cord  involvement  should  always  be  made,  and  if 
signs  are  found  they  are  an  indication  of  the  extent  and  the  severity  of  the 
injury.  Complete  evulsion  from  the  spinal  cord  is  more  apt  to  occur  than  in 
birth  injuries.  Consequently  in^  adults  there  is  less  chance  for  regeneration 
without  operation  and  less  indication  for  conservative  mechanical  treatment. 


BRACHIAL    PLEXUS  255 

Hence,  early  exploration  is  more  frecjuently  indicated.  Naturally  when  there 
is  evulsion  of  the  roots  or  rupture  within  the  intervertebral  foramina  nothing  can 
be  done,  yet  in  paralyses  of  such  amplitude  as  to  involve  the  entire  extremity  any 
gain  is  of  value,  and  an  exploration  is,  therefore,  warranted  if  any  doubt  exists. 
Stab  Wounds  and  Gunshot  Wounds. — While  these  injuries  are  less  frequent 
than  ru])ture  of  the  ])lexus  they  are  not  uncommon,  since  the  plexus  is  in  a 


Fig.  g8. — Splint  for  brachial  plexus  cases  applied.  It  transfers  the  weight  to  the  opposite 
shoulder  and  to  the  thigh  of  the  same  side.  The  splint  proper  is  made  from  ^I'e  iron.  The  canvas 
straps  are  held  in  place  with  eyelets.     (Buerki,  Archives  of  Neurology  and  Psychiatry,  1920.) 

relatively  exposed  position  in  the  posterior  triangle  of  the  neck,  and  does  not 
receive  the  muscular  or  bony  protection  usually  afforded  structures  of  such 
importance.  In  injuries  of  this  type  the  prognosis  is  better  than  in  birth  palsies 
or  ruptures  of  the  adult  plexus,  in  that  the  funiculi  are  interrupted,  more  or  less, 
at  one  level,  and  are  not  evulsed  from  the  spinal  cord,  or  interrupted  within  the 
distal  or  central  stump;  consequently  end-to-end  suture  offers  greater  oppor- 
tunity for  regeneration.     (See  Fig.  96.) 

A  large  percentage  of  such  injuries  recover  without  operation,  hence  some 
deem  it  better  judgment  to  defer  exploration  and  await  spontaneous  regenera- 
tion. However,  early  exploration  of  the  wound  and  conservative  correction  of 
the  field  offers  increased  opportunity  for  regeneration,  providing  the  mechanics 


256         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

of  the  operation  are  not  too  difficult,  as  may  be  the  case  in  the  presence  of  an 
extensive  scar  or  associated  lesions  of  the  great  vessels.  Exploration  is  par- 
ticularly difficult  in  injuries  involving  the  lower  cervical  roots.  For  adequate 
exposure  of  this  region  it  is  frequently  necessary  to  cut  through  the  clavicle; 
consequently  in  cases  of  this  type  operation  for  exploration  alone  would  hardly 
seem  indicated. 

The  surgical  and  mechanical  treatment  of  plexus  injuries  of  the  adult 
follow  in  general  those  given  for  obstetrical  paralysis.  In  some  adult  cases  in 
place  of  an  abduction  splint  such  as  is  shown  in  Fig.  88,  an  airplane  sphnt 
will  be  found  more  suitable.  In  adults  it  is  awkward  and  tiresome  to  wear  a 
splint  which  holds  the  arm  more  or  less  vertical. 

CERVICAL  RIBS 

Surgical  treatment  of  the  brachial  plexus  may  be  called  for  in  the  presence 
of  a  cervical  rib,  either  an  abnormal  first  thoracic  rib,  or  an  apparently  normal 
first  thoracic  rib  exerting  pressure  on  the  plexus.  The  seventh  cervical  or 
the  lower  cord  of  the  plexus  (eighth  cervical  and  first  thoracic)  is  most  usually 
involved,  causing  pain  and  other  sensory  changes  along  the  inner  side  of  the  arm, 
forearm  and  hand  with  atrophy  of  the  muscles  of  the  hand  and  weakness  in  some 
of  the  flexor  muscles  of  the  forearm.  Sargent  (1921)  found  that  the  segmental 
distribution  in  his  cases  was  as  follows: 

Sixth  cervical,  seventh  cervical  and  first  thoracic  in  six  cases. 

Seventh  cervical,  eighth  cervical  and  first  thoracic  in  fourteen  cases. 

Seventh  cervical  and  eighth  cervical  in  twelve  cases. 

Bramwell  (1903),  Stopford  and  Telford  (1919)  have  shown  that  an  appar- 
ently normal  first  thoracic  rib  may  produce  definite  signs  of  compression  of  the 
lower  cord  of  the  brachial  plexus  and  be  relieved  by  removal  of  part  of  the  rib. 

Anatomy. — In  the  embryo  the  development  of  the  brachial  plexus  precedes 
that  of  the  costal  structures  and  according  to  Wood  Jones  (1904)  prevents  the 
formation  of  a  cervical  rib  by  the  pressure  exerted  by  the  developing  plexus. 
With  the  more  cephalic  position  of  the  limb  bud  the  eft'ect  exerted  by  the  pre- 
fixed plexus  on  the  developing  normal  costal  structures  would  be  less  and  a 
cervical  rib  consequently  is  found  more  frequently  with  the  prefixed  than  the 
postfixed  variety  of  plexus.  However,  this  view  is  not  held  by  Todd  (191 2)  who 
maintains  that  costal  abnormalities  are  due  to  errors  in  segmentation  and  that 
differences  in  the  position  of  the  plexus  are  only  associated  anomalies.  Costal 
and  vertebral  anomalies  occur  together.  Dwight  (igoi)  explains  the  appear- 
ance of  costal  abnormahties  by  irregular  segmentations  with  intercalation  and 


CERVICAL    RIBS  257 

excalation  of  segments  making  it  difficult,  if  not  impossible,  even  in  a  cadaver,  to 
determine  whether  a  rudimentary  tirst  rib  is  a  cervical  or  a  first  thoracic  rib. 
Varieties  of  cervical  ribs  have  been  described  depending  on  the  shape  and  length 
of  the  rib,  which  may  vary  from  a  short  rudimentary  process  to  a  full  rib  extend- 
ing forward  to  articulate  with  the  first  normal  rib.  The  most  frequent  types  are 
those  with  a  short  rudimentary  process  fused  or  articulating  with  the  seventh 
cervical  vertebra  and  prolonged  to  the  first  rib  by  a  dense  fibrous  band,  the 
seventh  cervical  root  crossing  the  tip  of  the  process  and  the  eighth  cervical 
and  first  thoracic  passing  over  the  fibrous  prolongation.  Cervical  ribs  are 
found  in  about  i  to  2%  of  all  cadavers  and  according  to  Streissler  (1913)  they 
are  bilateral  in  67%  and  the  unilateral  are  on  the  left  side^^in  more  than  60%. 
They  are  found  more  frequently  in  women  than  in  men. 

Since  such  costal  anomalies  are  present  from  birth,  it  is  diflicult  to  under- 
stand why  the  first  appearance  of  nerve  pressure  signs  should  occur  only  later 
in  life,  generally  not  before  the  second  decade.  Possibly  with  complete  ossi- 
fication of  the  ribs  at  this  period  elasticity  is  diminished  and  with  greater  rigidity 
symptoms  may  occur.  Again,  a  low  grade  trauma  to  nerves  may  require  years 
before  any  clinical  signs  are  manifested.  It  has  been  frequently  observed  that 
years  after  fracture  of  the  elbow  ulnar  nerve  signs  may  appear  without  any  other 
injury.  (See  p.  369.)  In  like  manner  it  is  possible  that  pressure  e.xerted 
on  the  plexus  by  a  cervical  rib  may  give  clinical  signs  only  after  a  period  of 
years.  Todd  believes  the  development  of  late  symptoms  to  be  due  to  the  des- 
cent of  the  shoulder  girdle  to  a  more  caudad  position.  The  clavicle  is  lowered 
on  its  inner  end,  according  to  him,  by  the  action  and  pull  of  the  abdominal 
muscles  on  the  sternum,  while  the  outer  end  of  the  clavicle,  especially  in  women 
is  said  to  descend  at  puberty. 

Probably  signs  of  compression  in  the  absence  of  a  cervical  rib  may  be 
due  to  a  low  origin  of  the  plexus — postfixed  variety — with  a  relatively  large 
contribution  from  the  lowest  root  to  the  inner  cord.  Harris  (1904)  believes 
that  the  second  thoracic  nerve  contributes  motor  fibers  to  the  intrinsic  mus- 
cles of  the  hand  in  postfixed  plexuses  and  consequently  these  fibers  would 
be  more  in\-olved  than  others  by  pressure  over  an  apparently  normal  first 
thoracic  rib.  In  these  cases  a  negative  roentgen  ray  examination  does  not 
preclude  the  possibility  of  compression  of  the  lower  cord  of  the  plexus,  nor 
is  it  precluded  when  a  relatively  short  cervical  rib  is  found,  since  in  many  a 
fibrous  band  which  extends  forward  to  the  first  rib  may  cause  pressure  signs 
as  well  as  a  bony  process.     Dupre  and  Todd  (1914)  have  described  a  bilateral 


25S  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

rudimentary  cervical  rib  which  was  grooved  on  both  tlie  right  and  left  sides  not 
by  the  lower  cord  but  by  the  seventh  cer\ical  root,  the  lower  cord  lying  free 
beneath  the  cervical  rib  which  was  only  5  cm.  long.  Such  implication  of  the 
seventh  cervical  root  may  explain  the  appearance  of  compression  signs  along 
the  pre-axial  border  of  the  extremity  in  certain  cases  of  cervical  ribs.  However, 
signs  on  the  pre-axial  border  may  also  be  explained  by  involvement  of  the  fibers 
of  the  inner  cord  which  pass  through  the  inner  head  of  the  median  nerve  to 
supply  the  pre-axial  border. 

Deformity. — Atrophy  of  the  intrinsic  muscles  of  the  hand  and  weakness 
with  or  without  atrophy  of  the  flexor  muscles  along  the  postaxial  border  of  the 
forearm  are  found.  Wilson  (1903)  has  pointed  out  that  the  abductor  brevis 
and  opponens  pollicis  may  be  the  only  muscles  involved,  the  interossei  and  the 
remaining  thenar  muscles  showing  no  change.  This  muscular  involvement  is 
diiificult  to  explain.  (See  p.  235.)  Marked  circulatory  or  vasomotor  changes 
are  frequently  present  and  may  be  due  to  compression  of  sympathetic  libers  to 
the  vessels  of  the  extremity  within  the  nerve  trunk  or  to  direct  pressure  on  the 
subclavian  artery.  As  pointed  out  elsewhere  (see  Chapter  XX),  the  vessels  of 
the  extremity,  with  the  exception  of  the  subclavian,  are  supi>lied  by  nerve  fibers 
from  the  nerves  in  their  immediate  vicinity  and  not  by  continuous  perivascular 
sympathetic  fibers.  Consequently  an  irritative  lesion  of  the  lower  cord  of  the 
brachial  plexus  may  cause  extensive  vascular  changes  throughout  the  extremity 
by  involvement  of  the  postganglionic  sympathetic  efferent  libers  within  the 
nerve  trunk.  If,  on  the  other  hand,  the  A'ascular  changes  are  due  to  direct 
pressure  on  the  subclavian  artery,  the  circulation  may  be  impro\'ed  by  changing 
the  position  of  the  arm.  Also  a  difference  in  blood  pressure  and  pulse  on  the 
affected  side  will  be  noted  on  full  inspiration,  the  pulse  volume  and  blood  pres- 
sure being  diminished  on  inspiration  or  by  pulling  the  arm  downward.  Hal- 
stead  (1916)  found  direct  pressure  on  the  subclavian  artery  in  only  5'^f  of 
three  hundred  and  sixty  cases  studied.  Wood  Jones  (1904)  believes  that  the 
subclavian  groove  on  the  first  rib  does  not  lodge  the  subclavian  artery  but  the 
lower  cord  of  the  brachial  plexus  and  for  this  reason  suggested  that  the  sulcus 
subclaviae  be  named  sulcus  nervi  brachialis.  Consequently  pressure  eft'ects 
would  be  exerted  first  on  nerve  roots  and  not  on  the  subclavian  artery. 

Sensory  Changes. — Objective  sensory  changes  or  paresthesia  may  be  found 
along  the  postaxial  border  of  the  liml)  and  hand.  Occasionally  the  patient 
may  complain  of  awkwardness  in  the  performance  of  skilled  movements  of  the 
hand,  especially  noted  toward  the  end  of  the  day  after  the  arm  and  hand  have 


CERVICAL    RIBS  259 

been  in  use  for  some  time.  This  may  be  due  to  a  disturbance  in  the  proprio- 
ceptive mechanism  affecting  the  smaller  muscles  and  joints  of  the  hand.  In 
only  one  instance  have  I  been  able  to  detect  any  disturbance  of  vibratory 
or  muscle  joint  sense.  Stopford  and  Telford  have  pointed  out  that  in  some  of 
their  cases  dissociation  of  sensation  was  found  with  greater  loss  in  the  affective 
forms  of  sensation  (pain  and  temperature)  than  in  the  discriminative  (cotton, 
wool,  etc.).     Pain  may  be  a  prominent  symptom. 

In  an  admirable  study  of  fifty  cases  of  cervical  rib,  Percy  Sargent  concluded 
that:  "Variations  in  the  composition  of  the  brachial  plexus  are  apt  to  be  asso- 
ciated with  costal  abnormalities,  prefixation  with  a  seventh  cervical  rib  and 
postfixation  with  an  abnormal  tirst  thoracic  rib.  There  is,  however,  no  regular 
relationship  between  the  costal  and  neural  anomalies. 

"Of  the  several  different  types  of  cervical  rib  met  with  clinically,  that 
which  most  frequently  requires  treatment  by  operation  is  represented  by  an 
abnormally  large  nonjointed  costal  process,  continued  onward  as  a  dense  fibrous 
band,  to  be  attached  to  the  first  thoracic  rib  behind  the  .sulcus  nervi  brachialis 
(sulcus  subclaviae). 

"Symptoms  of  gradual  onset  from  continual  slight  traumatism  to  the 
eighth  cervical  root  or  the  lowest  cord  of  the  plexus,  caused  by  the  tightening 
of  the  band  during  respiration  and  in  certain  movements  of  the  arm. 

"With  a  postfixed  plexus  symptoms  referable  to  the  first  thoracic  root 
may  be  caused  by  the  pressure  of  a  normal  first  thoracic  rib. " 

Mechanical  Treatment. — This  is  of  little  value  except  in  cases  in  which 
the  symptoms  have  come  on  after  sudden  trauma  such  as  a  sudden  down- 
ward wrench  of  the  arm.  This  occurred  in  one  of  my  cases  when  a  heavy  chain, 
in  which  the  workman's  hand  had  become  entangled,  fell.  The  sudden  down- 
ward pull  produced  definite  signs  of  lower  cord  compression  which  were  relieved 
liy  placing  the  arm  in  a  plaster  in  an  elevated  position.  For  this  purpose  an 
airplane  splint  similar  to  that  used  for  deltoid  paralysis  will  also  be  found  service- 
able. (See  Fig.  98.)  However,  some  cases,  not  of  traumatic  origin,  have 
been  reported  in  which  an  elevated  position  of  the  arm  increased  the  vascular 
disturbances,  the  pulse  becoming  weaker  and  the  blood  pressure  lowered 
in  the  affected  arm.  Obviously,  when  such  signs  occur  the  elevated  position 
of  the  extremity  is  contraindicated. 

Surgical  Treatment. — For  short  rudimentary  processes  not  extending 
forward  a  dorsal  exposure  offers  a  means  of  approach,  but  for  more  complete 
(  orms  of  cervical  rib  a  lateral  exposure  is  to  be  preferred.    This  exposure  may  be 


26o         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

extended  dorsally  or  ventrally,  as  needed,  to  expose  the  ventral  end  of  the  rib  and 
search  for  fibrous  bands  which  may  extend  forward  to  the  first  rib  and  cause  the 
same  pressure  effects  as  a  complete  cervical  rib. 

Incision. — A  collar  incision  lo  to  12  cm.  long  is  made  beginning  in  front 
at  the  insertion  of  the  sternocleidomastoid  and  extending  backward  parallel 
to  the  clavicle  as  far  as  the  border  of  the  trapezius.  Taylor^  recommends 
an  oblique  incision  which,  lying  in  the  line  of  skin  cleavage,  will  leave  a 
linear  scar,  whereas  other  incisions  eventually  show  a  wide  scar,  even  though 
at  first  the  scar  may  appear  as  a  line.  This  is  a  worth  while  point,  since  in 
most  instances  the  condition  occurs  in  young  women. 

Exposure  of  the  Rib. — The  brachial  plexus  is  exposed  between  the  scalenius 
anticus  and  medius  and  the  great  vessels  are  identified.  The  plexus  as  a  whole 
is  retracted.  For  this  purpose  a  moist  piece  of  broad  tape  is  passed  and  clamped 
with  forceps  to  serve  as  a  retractor.  The  degree  of  tension  is  controlled  better 
in  this  manner  than  when  a  metal  retractor  is  used,  and  the  injury  incidental 
to  possible  slipping  of  the  retractor  is  avoided.  Tension  on  the  plexus  may 
cause  transitory  palsies,  perhaps  due  to  the  fact  that  the  pressure  is  exerted 
so  near  the  ventral  gray  cells.  In  freeing  the  ventral  part  of  the  rib  the  plexus 
is  retracted  dorsally  and  the  subclavian  artery  ventrally.  A  search  is  made 
for  any  bands  connecting  the  cervical  rib  with  the  first  rib.  The  insertion  of 
the  scalenius  muscles  and  the  intercostals  are  freed  from  the  rib  by  sharp  dis- 
section. When  the  ventral  part  of  the  rib  is  freed,  the  ventral  part  of  the  wound 
is  packed  and  the  dorsal  part  of  the  rib  is  then  exposed  in  the  dorsal  angle  of  the 
wound.  The  spinal  accessory  nerve  must  be  identified  in  this  part  of  the  opera- 
tion in  order  to  avoid  injury  of  it.  The  rib  may  be  followed  backward  and  an 
exposure  obtained  by  splitting  the  trapezius  muscle  and  retracting  the  levator 
scapulae  together  with  the  inner  part  of  the  split  trapezius.  The  muscular 
attachments  to  this  part  of  the  rib  are  then  freed  and  the  rib  exposed  as  far  as 
its  vertebra. 

Subperiosteal  resection,  although  simpler  to  do,  may  result  in  regeneration 
of  the  rib  as  de  Quervain  (1895),  Beck  (1905)  and  Lewis  (1918)  have  shown. 
In  freeing  the  rib  the  pleura  may  be  injured  and  possibly  the  vessels  and  nerves, 
consequently  this  makes  removal  of  a  structure  so  deeply  situated  as  a  cervical 
rib  an  operation  of  considerable  diffiiculty. 

The  results  of  operation  for  cervical  rib  are  entirely  favorable,  being  more 
favorable  the  earlier  the  operation,  particularly  as  regards  regeneration  of 
'In  a  paper  read  before  the  N.  Y.  State  Jledical  Society,  May  5,  iq2i. 


CERVICAL    RIBS  26 I 

atrophied  muscles.  Sargent  found  that  "vasomotor  symptoms  were  cured 
in  fourteen  cases,  relieved  in  six,  and  unrelieved  in  two;  pain  was  cured  in 
nineteen  and  relieved  in  eight;  muscular  wasting  was  cured  in  twelve  cases, 
relieved  in  twelve,  and  unrelieved  in  seven. "  It  is  but  fair  to  state  that  four 
of  those  unrelieved  were  lost  sight  of  before  recovery  of  the  affected  muscles 
could  have  taken  place. 

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Anat.  Anz.,  v.  41:  1912,  p.  257. 
"Cervical  rib:"  factors  controUing  its  presence  and  its  size,  its  bearing  on  the  morphology 
and  development  of  the  shoulder,  J.  .\nat.  &  Physiol.,  v.  46:  1912,  p.  244. 
Warrington,  W.  B.  and  Jones.  R.:  Some  observations  on  paralysis  of  the  brachial  plexus 

Lancet,  v.  2:  1906,  pp.  1644-49. 
Whitman,  R.:  Remarks  on  the  surgical  treatment  of  obstetrical  paralysis,  J.  Nerv.  &  Went. 
Dis.,  V.  31:  1904,  p.  497. 
The  treatment  of  congenital  and  acquired  luxation  of  the  shoulder  in  childhood,  Ann., 
Surg.,  v.  42:  1905,  p.  no. 
Wilson,  S.  A.  K.:  Some  points  in  the  symptomatology  of  cervical  ribs  with  special  refer- 
ence to  muscular  wasting,  Proc.  Roy.  Soc.  Med.,  1913,  6  (Clin.  Sect.),  p.  133. 


CHAPTER  XII 
MUSCULOSPIRAL  NERVE 

Anatomy. —  The  musculospiral  nerve,  the  direct  continuation  of  the  dor- 
sal cord  of  the  brachial  plexus,  is  derived  from  the  dorsal  branches  of  the 
ventral  primary  divisions  of  the  last  four  cervical  nerves.  It  also  receives, 
according  to  Harris  (1903),  a  small  dorsal  branch  from  the  first  thoracic  nerve. 
The  musculospiral  nerve  supplies  the  primitive  dorsal  musculature  of  the 
upper  extremity,  giving  also  a  small  branch  to  the  brachialis  muscle.  This 
muscle,  in  its  origin,  is  a  fusion  of  both  dorsal  and  ventral  musculature,  hence 

the  dual  innervation. 

Course. — In  its  upper  part  the  musculospiral  nerve  passes  across  the  ven- 
tral surface  of  the  latissimus  dorsi  and  teres  major  tendons  beneath  the  axillary 
artery  and  enters  the  fascial  plane  between  the  long  and  lateral  heads  of  the 
triceps,  lying  close  to  the  inner  side  of  the  humerus,  and  thence  descends  to 
the  dorsum  of  the  humerus,  in  the  spiral  groove  beneath  the  lateral  head  of  the 
triceps.  At  the  junction  of  the  lower  and  middle  thirds  of  the  humerus  it 
pierces  the  lateral  intermuscular  septum  and  passes  ventral  between  the  supi- 
nator longus  and  the  brachialis  muscles,  where  it  descends  almost  vertically  to 
the  lateral  condyle,  at  which  point,  or  slightly  above,  it  divides  into  its  two 
terminal  branches,  the  posterior  interosseous  and  the  radial  nerves. 

Within  the  musculospiral  groove,  the  nerve  is  accompanied  by  the  external 
cutaneous  nerve  and  the  superior  profunda  artery.  Upon  reaching  the  outer 
side  of  the  humerus  this  artery  divides  into  two  branches:  a  smaller,  which 
accompanies  the  nerve  through  the  intermuscular  septum,  and  a  larger  branch, 
which  runs  downward  on  the  dorsal  surface  of  the  intermuscular  septum  to  the 
lateral  condyle.  The  course  of  the  nerve  is  more  nearly  vertical  than  one  is  led 
to  suppose  from  the  usual  anatomical  descriptions.  It  is  spiral  only  in  a  small 
portion  of  its  middle  third;  in  its  upper  and  lower  thirds  it  is  almost  perpendic- 
ular— a  point  worth  recalling  in  exposure  of  the  nerve.     (See  Fig.  99.) 

Variations  in  the  course  of  the  musculospiral  are  extremely  rare.  The 
nerve  has  been  observed  to  pass  with  the  circumflex  through  the  quadrilateral 
space,  to  enter  the  musculospiral  groove.  The  posterior  interosseous  nerve 
may  pass  over  the  supinator  brevis  muscle  instead  of  through  or  beneath  it. 

265 


266         SURGICAL    AXD    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Branches. — Three   sets  of  branches   arise  from  the  musculospiral  nerve 


Fig.  99. — Musculospiral  nerve — surface  projection  i,  i',  i",  Circumflex  nerve;  2,  nerve  to 
long  head  of  triceps;  3,  nerve  to  outer  head  of  triceps;  4,  nerve  to  inner  head  of  triceps  and  anconanis; 
5,  superior  external  cutaneous;  5',  inferior  external  cutaneous;  6,  posterior  interosseous;  7,  radial; 
8,  branch  to  extensor  carpi  radialis  brevis;  9,  9',  branch  to  supinator  brevis;  10,  branch  to  extensor 
digitorum  communis,  extensor  digiti  quinti  proprius,  and  extensor  carpi  ulnaris;  11,  branch  to  abduc- 
tor pollicis  longus,  extensor  poUicis  longus;  12,  branch  to  extensor  pollicis  brevis;  13,  branch  to  e.xtensor 
indicis  proprius  (lower  head). 

respectively  from  its'position  as  it  lies  medial,  dorsal  and  lateral  to  the  humerus. 
Those  of  the  medial  group  arise  in  close  proximity  to  each  other  as  the  nerve 


MUSCULOSPIRAL    NERVE 


267 


Fig.  100.— Triceps  muscle,  nerve  distribution  seen  from  the  under  surface.     (Frohse  and  Frankel.) 


268         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

crosses  over  the  tendon  of  the  UUissimus  dorsi  muscle.  These  branches  are  the 
internal  cutaneous,  a  muscular  branch  to  the  long  head  of  the  triceps,  and  the 
ulnar  collateral  to  the  media!  head  (r.  collateralis  n.  ulnaris  n.  radialis,  Krause, 
1864).  (See  Fig.  100.)  Those  of  the  dorsal  group  are  the  muscular  branch  to 
the  lateral  head  of  the  triceps,  one  to  the  lateral  part  of  the  medial  head,  the 
anconseus,  and  the  elbow  joint,  and  the  superior  and  inferior  external  cutaneous 
branches  to  the  lateral  part  of  the  arm  and  dorsum  of  the  forearm.  The 
branches  of  the  lateral  group  are  distributed  to  the  brachialis,  supinator  longus 
and  to  the  extensor  carpi  radialis  longus  and  brevis.     (See  Fig.  loi.) 

By  finer  dissection  and  tracing  the  branches  within  the  epineurium  in 
macerated  specimens  Borchardt  and  Wjasmenski  (1919)  have  shown  that  as  the 
nerve  lies  on  the  tendon  of  the  latissimus  dorsi,  the  libers  for  the  external 
cutaneous  nerves  lie  medial  to  the  nerve  trunk,  cross  lateral  and  then  run  with 
the  main  nerve  trunk  around  the  humerus  in  the  spiral  groove.  The  internal 
cutaneous  arises  from  this  nerve  bundle.     (See  Fig.  102.) 

The  next  bundle  to  arise  is  the  muscular  branch  to  the  lateral  head  of  the 
triceps,  to  the  lateral  part  of  the  medial  head  and  the  ancona;us.  Adjacent  to 
this  bundle  is  the  motor  funiculus  for  the  long  head  of  the  triceps,  from  which 
arises  also  the  ulnar  collateral  and  the  branches  to  the  medial  head. 

Thus,  it  will  be  seen  that  there  are  three  main  bundles  in  the  musculo  spiral 
nerve  in  the  arm,  from  which  others  arise  as  secondary  branches.  All  the  cu- 
taneous sensory  branches  arise  from  one  common  bundle;  the  muscular  branches 
to  the  lateral  head,  part  of  the  medial  head  and  the  anconasus  as  well  as  afferent 
to  the  elbow  joint  from  a  second,  the  branch  to  the  long  head,  and  the  ulnar 
collateral  from  a  third. 

The  branches  given  off  from  the  nerve  as  it  lies  ventral  to  the  intermuscular 
septum  are :  the  branch  to  the  supinator  longus — occasionally  two  arising  5  or  6 
cm.  above  the  medial  condyle,  and  from  the  lateral  border  of  the  nerve;  and  the 
branch  to  the  brachialis  muscle  from  the  medial  border  at  the  same  level.  (See 
Fig.  103.)  This  branch  Frohse  and  Frankel  (1908)  found  in  more  than  75%, 
while  Borchardt  and  Wjasmenski  (1919)  met  it  only  once  in  more  than  fifty  dis- 
sections. Such  variance  seems  difficult  to  explain.  However,  it  must  be 
recalled,  as  has  already  been  pointed  out,  that  the  brachialis  is  formed  by  fusion 
of  elements  originally  both  ventral  and  dorsal.  These  components  may  be 
unequal  or  either  absent,  with  a  proportionate  variation  in  nerve  supply. 

The  branch,  or  two  branches,  to  the  extensor  carpi  radiaUs  longus  arise 
about  I  cm.  below  that  to  the  supinator  longus  and  like  the  latter  lie  on  the 


MUSCULOSPIRAL    NERVE 


269 


N.  radialis  communis 


M.  brachioradialis 


R.  superficialis  n.  radialis 


M.  extensor  carpi 
radialis  longus 


R.  profundus   n.  radialis 


M.  extensor  digi- 
torum  communis 


M.  extensor 
iigiti  V 


M.  extensor r 

indicis  proprius 


Fig.  loi.—Distribution  of  the  musculospiral  nerve  to  the  muscles  of  the  forearm.     (Frohse  and 

Frankeh) 


270         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Fig.  102. — Musculospiral  ner\'e.  Dissection  of  macerated  specimen.  E,  Level  of  elbow;  i 
posterior  interosseous;  2,  superficial  radial;  3,  branch  to  brachio-radialis;  4,  branch  to  extensor  carpi 
radialis  longus;  5,  branch  to  extensor  carpi  radialis  brevis;  6,  branches  for  supinator  brevis.  (Bor- 
chardt  and  Wjasmenski,  Beitr.  z.  klin.  Chir.,  1919.) 


MUSCULOSPIRAL    XERVE 


271 


Fig.  103. — Musculospiral  nerve.  Dissection  of  macerated  specimen.  E,  Level  of  elbow;  i: 
posterior  interosseous;  2,  superficial  radial;  3,  branch  to  brachio-radialis;  4,  branch  to  extensor  carpi 
radialis  longus;  5,  branch  to  extensor  carpi  radialis  brevis;  6,  branches  for  supinator  brevis;  7,  branch 
to  extensor  digitorum  communis,  extensor  digiti  quinti  proprius,  extensor  carpi  ulnaris;  8.  branch 
to  extensor  pollicis  longus,  abductor  poUicis  longus;  9.  terminal  branch  to  the  carpus;  10,  branch  to 
extensor  pollicis  longus      (Borchardt  &  W'jasmenski,  Beitr.  z.  klin.  Chir  ,  igig.) 


272         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

radial  border  of  the  nerve.  The  same  funiculus  gives  rise  to  the  branches  to  the 
extensor  radialis  longus  and  brevis.  The  branch  to  the  latter  muscle  descends 
as  a  separate  bundle  a  short  distance  within  the  nerve  adjacent  to  the  superficial 
radial  and  has  a  long  extraneural  course  before  entering  its  muscle,  while  the 
other  branches  in  this  region  enter  almost  immediately  the  muscles  which  they 
supply.  This  branch  is  of  considerable  importance  in  view  of  its  supply  to  the 
extensor  carpi  radialis  brevis,  which  is  a  more  powerful  extensor  of  the  wrist 
than  its  companion  muscle,  the  extensor  carpi  radialis  longus;  consequently 
every  effort  should  be  made  to  sa\'e  this  branch  or  to  suture  it  separately. 
(See  Fig.  114.) 

Terminal  Branches. — The  musculospiral  nerve  terminates  a  few  centi- 
meters above  the  lateral  condyle  by  dividing  into  the  radial  and  the  posterior 
interosseous,  nerves.  The  radial  nerve  lies  medial  and  in  front;  the  posterior 
interosseous,  dorsal  and  lateral.  This  relationship  identifies  at  this  level  these 
two  nerves  approximately  the  same  in  size. 

The  posterior  interosseous  nerve  descends  in  the  cleft  between  the  supinator 
longus  and  the  brachialis  muscles,  then  beneath  the  extensor  carpi  radialis 
longus  and  bre\4s  to  the  outer  side  of  the  radius  around  which  it  passes  obliquely 
and  pierces  the  supinator  brevis  muscle  to  wliich  it  contributes  several  branches. 
One  to  two  cm.  below  its  exit  from  the  supinator  brevis  muscle,  the  posterior 
interosseous  nerve  terminates  by  dividing  into  two,  or  sometimes  three  or  four, 
main  branches  which  in  turn  rapidly  redivide.  The  nerve  in  its  course  around 
the  radius  becomes  flattened  and  broad,  more  or  less  losing  its  appearance  as  a 
nerve.  The  terminal  branches  are  a  relatively  large  branch  of  short  extra- 
muscular  course  which  supplies  the  extensor  digitorum  communis  the  extensor 
carpi  ulnaris  and  extensor  digiti  quinti  proprius;  while  the  second  group  of 
terminal  branches  have  a  long  extramuscular  course  and  supply  the  abductor 
pollicis  longus,  extensor  poUicis  brevis  and  extensor  indicis  proprius.  These 
terminal  branches  are  so  small  that  it  is  rarely  possible  to  suture  them,  especially 
if  they  are  in  scar  tissue  from  which  they  must  be  dissected.  Generally  speak- 
ing, if  the  site  of  the  injury  is  more  than  6  cm.  below  the  lateral  condyle,  there  is 
little  chance  for  successfulnervesutureif  scartissueorcallusispresent.  In  these 
cases  tendon  transplantation  should  be  done  without  attempting  nerve  suture. 

Within  the  posterior  interosseous  nerve,  immediately  above  the  level  at 
which  its  terminal  branches  are  given  oft",  the  funiculi  are  closely  interwoven 
forming  an  internal  nerve  plexus,  making  differentiation  into  distinct  bundles 
and  funicular  separation  impossible. 


MUSCULOSPIRAL    NERVE 


273 


^^rt^/a  ^ 

• 
• 

J 

m 
> 

Fig.  104. — Musculospiral  nerve  right,  left,  from  same  individual.  Cross  sections  made  at  2-cm. 
intervals.  Note  that  the  cross  section  appearances  are  not  comparable  except  in  the  middle  third, 
though  made  at  corresponding  levels  in  the  same  individual.  F.,  Level  of  elbow;  i,  posterior  inter- 
osseous; 2,  superficial  radial;  3,  branch  to  brachio-radialis;  4,  branch  to  extensor  carpi  radialis  longus; 
5,  branch  to  extensor  carpi  radiahs  brevis;  6,  branches  for  supinator  brevis.  (Borchardt  and 
Wjasmenski,  Beitr.  z.  klin.  Chir.,  igig.) 


274         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Nerve  Plexuses. —  There  are  three  main  internal  nerve  plexuses  within  the 
musculospiral  nerve:  the  first  just  above  the  level  at  wliich  the  highest  group  of 
branches  is  given  off,  the  second  immediately  above  the  branches  to  the  supi- 
nator longus  and  the  third  in  the  upper  part  of  the  posterior  interosseous. 
Thus  there  is  a  relatively  long  intermediate  region  or  "zone  nodale"  in  which  the 
funiculi  are  assembled  into  a  few,  or  even  a  single,  nerve  bundle.  The  cross 
section  appearance  of  relatively  the  same  level  varies  in  different  individuals 
(see  Fig.  104),  and  even  in  the  same  individual  between  the  right  and  left 
nerves.  "When  one  compares  the  cross  sections  on  the  left  with  those  on 
the  right,  they  are  found  to  be  in  no  wise  congruent  in  spite  of  their  being  e.xact 
parallel  preparations"  (Borchardt  and  Wjasmenski,  1919).  This  lack  of  corre- 
spondence of  the  cross  sections,  and  the  numerous  intercommunications  of 
the  funiculi,  make  it  impossible  with  our  present  knowledge  to  localize  with 
exactness  the  various  funiculi  within  the  musculospiral  nerve  on  a  topograph- 
ical and  anatomical  basis.  However,  Borchardt  and  Wjasmenski,  Marie, 
Gosset  and  Meige  (1915)  were  able  to  localize  by  electrical  stimulation  libers  to 
the  extensors  of  the  wrist  upon  the  lateral  quadrant  and  libers  to  the  supinator 
on  the  medial  quadrant.  It  must  be  remembered  that  localization  by  the 
electrode  applies  only  to  the  nerve  e.xposed  at  the  time  of  operation,  and  it  is 
impossible  to  compare  accurately  with  the  same  nerve  of  other  individuals. 

On  cross  section  at  most  levels  the  musculospiral  nerve  shows  compara- 
tively few  funiculi,  consequently  in  nerve  suture  crossing  of  the  funiculi,  and 
loss  of  neuraxes  in  the  interstices  between  the  funiculi,  is  less  apt  to  occur  than 
in  those  nerves  in  which  the  funiculi  are  smaller  and  more  numerous,  such  as 
the  ulnar  nerve.  There  are  relatively  few  cutaneous  sensory  and  sympathetic 
fibers  within  the  musculospiral  nerve  and  the  muscles  supplied  are  large  and  do 
not  perform  the  liner  skilled  movements.  These  factors  may  contribute,  in  a 
measure  at  least,  to  the  excellent  results  obtained  from  suture  of  this  nerve. 

Anomalies  of  Distribution. — The  musculospiral  nerve  is  the  only  nerve  in 
the  upper  extremity  arising  from  the  dorsal  divisions  of  the  brachial  plexus,  and 
since  dorsal  divisions  innervate  only  dorsal  musculature  it  is  the  sole  supply  of 
all  the  dorsal  musculature.  It  is  a  distinct  unit  functionally  and  morphologic- 
ally in  its  comparative  anatomy  and  development,  which  probably  accounts  for 
the  fact  that  variations  in  its  distribution  occur  less  often  than  in  any  other  nerve 
of  the  upper  extremity.  When  two  nerves  have  arisen  from  a  common  nerve 
trunk  in  their  development,  as  have  the  musculocutaneous  and  the  median, 
variations  in  distribution  and   communications  are  apt  to  occur.     Another 


MUSCULOSPIRAL   NERVE  275 

source  of  variation  in  nerve  distribution  may  arise  when  more  than  one  nerve 
supplies  a  primitive  muscle  mass.  This  is  true  of  the  ventral  musculature  of 
the  upper  extremity  which  is  supplied  through  three  nerves  arising  from  the 
ventral  divisions  of  the  brachial  plexus,  namely,  musculocutaneous,  median  and 
ulnar  nerves,  while  the  dorsal  musculature  is  supplied  by  the  musculospira!  alone. 

DORSAL  CORD  INJURIES 

Deformity. —  Injuries  to  the  sc\-enth  cervical  root,  the  primary  middle  trunk 
or  the  dorsal  cord  all  result  in  total  or  peratial  paralysis  of  the  musculospiral,  sub- 
scapularis  and  circumflex  nerves.  In  this  paralysis  the  supinator  longus  may 
escape  unless  the  fibers  from  the  fifth  and  sixth  cervical  nerves  to  this  muscle 
are  injured  at  the  point  where  they  join  the  dorsal  cord,  and  this  differentiates 
injuries  here  from  more  peripheral  ones  in  which  the  supinator  is  paralyzed 
without  involvement  of  the  circumflex  and  subscapular  nerves.  In  complete 
dorsal  cord  injuries  the  subscapularis,  latissimus  dorsi,  teres  major,  deltoid, 
are  paralyzed  the  triceps  and  extensors  of  the  wrist,  fingers  and  thumb  may  be 
but  partially  paralyzed.  In  the  more  distal  injuries  the  subscapular  nerves 
may  escape. 

The  resulting  deformity  of  such  an  injury  is  essentially  loss  of  abduction, 
of  extension  of  the  forearm,  as  well  as  of  extension  of  the  fingers,  wrist  and 
thumb.  The  arm  hangs  in  adduction,  usually  with  very  little  inward  rota- 
tion, and  the  humerus  is  drawn  forward  by  contraction  of  the  pectoralis  major 
muscle.  Due  to  paralysis  of  the  triceps  and  the  supinator  the  forearm  is  slightly 
flexed  and  in  semipronation,  though  it  may  be  actively  supinated  by  means  of 
the  biceps  muscle.  The  wrist  falls  to  a  typical  wrist-drop  position,  and  the 
thumb  and  fingers  cannot  be  extended.  The  motor  loss  is  extensive  since  all 
of  the  dorsal  musculature  is  involved. 

Mechanical  treatment  should  endeavor  to  relax  the  deltoid  muscle  and  the 
extensors  of  the  forearm,  wrist  and  fingers  and  overcome  the  effects  of  gra\'ity. 
This  may  be  accomplished  by  placing  the  arm  in  abduction,  with  the  forearm 
slightly  flexed  and  the  wrist  and  proximal  phalanges  dorsiflexed  to  about  50.° 
The  sphnt,  shown  in  Fig.  105  is  similar  in  construction  to  appliances  used  for 
paralysis  of  the  fifth  and  sixth  cervical  roots.  Due  to  its  anatomical  arrange- 
ment the  triceps  is  not  apt  to  be  overstretched,  hence  the  forearm  may  be  held 
fully  extended  or  in  semiflexion.  However,  on  account  of  gravity,  and  adaptive 
shortening  of  the  flexors,  the  extensors  of  the  wrist  and  fingers  are  severely 
overstretched  and  undergo  marked  regressive  changes  unless  properly  splinted. 


276         SURGICAL    AXD    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

In  complete  dorsal  cord  injuries  an  objection  may  be  offered  to  splinting  the  arm 

in  abduction  since  by  so  doing  the  teres  major,  latissimus  dorsi,  and  subscapu- 

laris  muscles  are  not  relaxed,  but  it  is  impossible  to  relax  at  the  same  time  both 

abductors  and  adductors.     When  a  choice  must  be  made,  the  muscles  of  greatest 

value  should  receive  first  consideration.     The  function  of  the  deltoid  is  of  greater 

importance  in  the  movements  of  the  upper  extremity  than  that  of  the  adductors. 

Unsupported  the  paralyzed  deltoid  is  subject  to  greater  strain  and  overstretching 

than  are  the  other  muscles  and  consequently  greater  attention  should  be  paid 

to  the  more  important  deltoid. 

1 


Fig.  105. — Splint  for  total  or  partial  paralysis  of  the  dorsal  cord  and  musculospiral  nerve.  Adjus- 
table aluminum  abduction  splint  with  forearm  piece  to  maintain  the  wrist  in  dorsiflexion.  Arm  held 
in  abduction  with  the  wrist  dorsiflexed.     (Stookey,  Surgery,  Gynecology  and  Obstetrics,  1918.) 

INJURY  OF  THE  MUSCULOSPIRAL  NERVE 

Deformity.—  In  injuries  of  the  musculospiral  nerve  below  the  circumflex, 

complete  paralysis  of  the  supinator  longus,  extensors  of  the  wrist,  fingers  and 

thumb  occurs,  while  the  triceps  generally  shows  only  partial  paralysis,  since 

the  branches  to  the  long  head  of  the  latter  muscle  come  off  relatively  high,  and 

hence  one  head  of  the  triceps  may  escape. 

The  main  deformity  of  this  paralysis  is  wrist-drop.     In  cases  with  extreme 

atony  of  the  extensors,  the  wrist  falls  almost  to  a  right  angle.     When  neglected, 

edema  over  the  dorsum  of  the  wrist  takes  place  and  subluxations  about  the 

carpus   may    occur.     Without   mechanical    treatment    the    extensor   muscles 

become  greatly  overstretched,  due  both  to  gravity  and  the  unopposed  action 

of  the  flexors.     It  must  be  remembered  that  the  flexor  muscles  of  the  extremities 

are  stronger  than  the  extensors.     This  difference  in  strength  is  seen  in  many 

reflex  contractures  in  joint  injuries  in  both  the  upper  and  lower  extremities, 

in  which  the  deformity  is  usually,  flexion  deformity.     This  is  seen  at  the  hip,  as 

well  as  at  the  knee  and  the  ankle  of  the  lower  extremity,  and  at  the  elbow  and 


MUSCULOSPIRAL    NERVE  277 

wrist  of  the  upper.  The  extensors  of  the  wrist  and  fingers  and  the  ankle  and 
toes  arc  newer  acquisitions,  and  there  is  some  evidence  to  indicate  that  muscles 
of  more  recent  origin  are  more  \-ulncrable. 

Mechanical  Treatment. — Correction  of  the  deformity  in  musculospiral 
paralysis  consists  essentially  in  preventing  wrist-drop.  Even  after  successful 
repair  of  the  nerve,  return  of  motor  function  is  immeasurably  delayed  unless 
overstretching  is  prevented.  To  accomplish  this,  numerous  appliances  to 
maintain  the  wrist  and  first  phalanges  in  extension  have  been  devised.  There 
is  no  need  to  elevate  the  second  and  third  phalanges,  since  extension  of  these 
is  accomplished  by  the  interossei  muscles  acting  upon  the  extensor  tendons. 
To  obtain  the  optimum  relaxation,  the  wrist  and  proximal  phalanges  should 


Fig.  106^1. — Wrist-drop  splint  applied.  Thumb  is  held  extended  in  a  plane  with  the  rest  of  the 
lingers;  distal  two  phalanges  are  left  free  so  as  to  permit  normal  movement.  No  bandages  are 
necessary  to  hold  the  splint  in  place.     (Buerki,  Archives  of  Neurology  and  Psychiatry,  1920.) 


be  elevated  to  about  50°.  All  splints  should  include  the  thumb,  since  the 
extensors  to  the  thumb  are  also  implicated,  and  it  should  be  held  not  only 
in  extension  but  in  abduction  as  well.  Frerjuently  the  thumb  is  merely  pushed 
back  to  the  same  plane  as  the  metacarpal  bones  and  held  in  adduction. 
Contraction  in  this  position  causes  considerable  disability. 

Appliances  which  hold  the  wrist  straight  and  in  line  with  the  forearm  are 
not  efficient,  as  they  do  not  prevent  overstretching.  Some  appliances  seek 
to  replace  the  action  of  the  extensor  tendons  by  rubber  tubes  or  flexible  metal 
springs.  These  are  very  convenient  and,  so  far  as  motion  is  concerned,  satis- 
factory, in  that  they  j^ermit  the  patient  to  make  use  of  his  hand  in  grasping- 
Whatever  the  appliance  used,  it  is  essential  that  the  wrist  at  rest  always  be 
elevated  to  about  50°  and  any  range  of  motion   given  it  must   start    from 


278         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

this  point.     Splints  which  are  dorsally  placed,  leaving  the  palm  unobstructed, 
are  more  satisfactory  for  they  permit  greater  use  of  the  hand. 


Fig.  106B. — Splint  for  wrist-drop  with  extra  piece  to  support  palmar  arch.  .1 ,  Adhesive  band 
which  fits  on  dorsal  surface  of  wrist;  B,  removable  canvas  band  which  fits  on  anterior  surface  of 
forearm;  C,  palmar  piece  to  maintain  palmar  arch  held  to  the  main  splint  by  adhesive  plaster. 
(Buerki,  .\rchives  of  Neurology  and  Psychiatry,  1920.) 

The  appliances  illustrated  (Figs.  106,  107)  show  their  relative  merits  and 
need  no  further  explanation.^  Perhaps  those  splints  are  to  be  preferred  which 
not  only  maintain  adequate  elevation  of  the  wrist  and  fingers,  but  also  permit 


'iimiiininnim,.,.,,! ini,iLiiniiii,»ii)ii 


Ti))M)fm^-'-''«'«'>'''-'^"^^^^^^^^^ 


Fig.  107. — Splint  for  wrist-drop.  (Modified  from  Privat  and  Belot.)  The  splint  is  made  of 
spring  steel  wire.  At  the  level  of  the  wrist  joint  the  wires  are  flattened  and  a  joint  made.  A  single 
or  bilateral  spring  or  rubber  band  offers  an  elastic  support  to  the  wrist  in  place  of  a  fi.\-ed  support. 
In  musculospiral  paralysis  the  palmar  arch  is  unaffected,  hence  a  palmar  piece  to  maintain  the 
palmar  arch  is  superfluous. 

limited  flexion.  Apart  from  the  convenience  of  being  able  to  flex  the  wrist 
and  fingers,  a  certain  physiological  function  is  also  served  by  flexion  and  the 
passive  recoil  to  extension  of  the  paralyzed  muscles.  By  passive  movements 
the  circulation  of  the  paralyzed  muscle  is  increased  with  an  attendant  increase  in 
removal  of  waste  products  and  an  improvement  in  the  nutrition.     By  these 

'  See  Privat  and  Belot;  Prothese  musculaire,  Paris  Jledicale,  Feb.,  1917,  p.  143,  for  an  excellent 
series  of  similar  spring  steel  wire  splints  for  wrist  drop  and  foot  drop. 


MUSCULOSPIRAL    NERVE 


279 


passive  movements  the  mobility  of  the  tendons  in  tlie  tendon  sheaths  is  main- 
tained and  contractures  about  the  joints  are  less  apt  to  occur. 


Teres  "ia 

tenion 


Fig.  108. — Exposure  of  the  musculospiral  nerve  behind  the  humerus  and  immediately  below 
the  teres  major  tendon  (seen  from  behind  with  the  arm  held  at  right  angles  to  the  body).  The 
foreign  body  imbedded  in  the  nerve  caused  a  dissociated  paralysis.  Note  the  marked  increase  in  the 
small  vessels  on  the  nerve. 


Dissociated  paralyses  of  various  types  may  be  found  when  partial  injury 
to  the  nerve  trunk  occurs.  In  one  of  my  cases  the  extensors  of  the  wrist,  inde.x 
fingers,  and  third  fingers  were  paralyzed  while  the  extensors  of  the  thumb,  fourth 
and  fifth  fingers  were  intact.     At  operation  a  foreign  body  was  found  imbedded 


28o 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


in  the  nerve  involving  but  part  of  the  nerve  trunk.  (See  Fig.  io8.)  Similar 
dissociated  paralyses  have  been  described  by  Marie,  Meige  and  Patrikoos  (1917) 
and  Rousey  and  Branch  (1917).  In  their  cases  the  paralysis,  on  superficial 
examination,  simulated  injury  to  the  ulnar  nerve,  for  only  the  last  two  fingers 
were  involved. 

Exposure  of  the  musculospiral  nerve  above  the  lower  border  of  the  lat- 
issimus  dorsi  and  teres  major  tendons  is  accomplished  in  much  the  same  manner 
as  exposure  in  low  plexus  injuries. 


^*'  SuUc,»-f>ulsJ-N! 


Bt-  fo  lorlC;  heid 


Circumflex  N. 


I'lG.  loy. — Exposure  ami  suture  ol  llie  dorsal  cord  of  the  brachial  plexus.  The  small  veins  and  a 
few  of  the  arteries  on  the  axillary  wall  have  been  cut  to  permit  retraction  of  the  neurovascular  bundle. 
The  circumflex  nerve  has  been  freed  up  the  sheath  of  the  dorsal  cord  and  separately  sutured. 


Position  of  tlie  Arm. — The  arm  is  held  in  external  rotation  and  at  a  right 
angle  with  the  body  with  the  forearm  extended  in  semipronation.  A  fiat 
sandbag  is  placed  beneath  the  shoulder. 

The  incision  begins  across  the  pectoralis  major  muscle,  in  the  cleft  between 
it  and  the  deltoid,  and  is  carried  downward  into  the  axilla  on  the  medial  surface 
of  the  arm  along  the  line  of  the  great  vessels.  In  some  instances,  it  may  be 
preferable  to  make  the  incision  entirely  within  the  axilla,  beginning  at  the 
middle  of  the  axilla  and  carrying  it  downward  along  the  inner  margin  of  the 
coracobrachialis  muscle.  In  exposing  the  nerve  the  branches  which  lie  upon 
the  ventral  surface  of  the  latissimus  dorsi  tendon,  and  medial  to  the  main 


MUSCULOSPIRAL    NERVE  28  I 

nerve  trunk,  must  be  avoided.  The  branches  which  arise  from  the  nerve  in 
this  region  are,  in  the  order  of  their  appearance,  the  internal  cutaneous,  branch 
to  the  long  head  of  the  triceps,  ulnar  collateral  for  the  inner  head  of  the  triceps 
and  anconaeus,  and  a  branch  for  the  lateral  head  of  the  triceps.  (See  Fig.  109.) 
The  nerve  may  be  exposed  by  going  between  the  axillary  vein  and  the  median 
nerve,  or  the  entire  neurovascular  bundle  may  be  retracted  laterally,  exposing 
the  musculospiral  nerve  beneath.  The  vessels  may  be  retracted  either  down- 
ward and  inward,  or  upward  and  outward  after  cutting  the  small  veins  from 
the  anterior  axillary  wall,  thus  freeing  the  vessels.  The  direction  of  the  nerve 
is  outward  and  downward,  which  makes  retraction  of  the  vessels  in  the  opposite 
direction  usually  preferable.  By  following  up  the  border  of  the  latissimus 
dorsi  tendon  the  musculospiral  nerve  will  readily  be  found  lying  upon  the 
ventral  part  of  the  tendon.  Occasionally  there  is  a  muscular  slip  from  the 
latissimus  dorsi  to  the  triceps  or  coracobrachialis.  This  muscular  slip  may 
be  so  prominent  as  to  confuse  the  anatomical  field.  The  axillary  vein  is  formed 
by  the  junction  of  the  two  venas  comities,  occuring  usually  at  the  lower  border 
of  the  latissimus  dorsi  tendon,  though  it  may  be  higher  or  lower  than  this.  If 
the  basilic  vein  has  not  already  joined  the  inner  vena  comes,  three  veins  may 
be   found.     At  a  higher  level   the  cephalic  vein  appears. 

Exposure  of  the  Musculospiral  Nerve  in  the  Arm. — It  is  frequently  neces- 
sary to  expose  the  nerve  over  a  large  part  of  its  course,  especially  in  fracture  of 
the  humerus  with  inclusion  of  the  nerve  over  a  considerable  length  in  scar  and 
callus.  The  more  usual  method  of  exposure  is  by  means  of  a  spiral  incision, 
following  more  or  less  the  supposed  line  of  the  nerve. 

There  are  certain  disadvantages  in  this  incision,  for  it  is  rather  difficult  to 
place  a  spiral  incision  exactly  over  the  course  of  the  nerve,  and  considerable 
difficulty  may  be  met  with  in  locating  it.  This  is  the  disadvantage  of  an 
incision  which  runs  parallel  to  any  nerve  which  follows  a  winding  or  spiral 
course.  In  addition,  in  the  spiral  incision  to  expose  the  musculospiral  nerve 
part  of  the  triceps  muscle  must  be  cut  transversely.  While  such  transverse 
section  of  a  muscle  may  not  cause  extensive  paralysis,  permanent  partial 
paralysis  may  result,  especially  if  the  incision  should  encounter  a  motor  branch. 
The  loss  of  part  of  the  triceps  might  not  be  of  any  consequence  alone,  but  where 
paralysis  of  other  muscles  already  exists  it  is  preferable  to  avoid  inflicting'an 
additional  paralysis.  If  the  incision  is  directly  over  the  nerve,  it  places  the 
nerve  in  the  line  of  the  scar.  Consequently  it  is  preferable  to  place  the  skin 
incision  so  that  it  does  not  fall  directly  over  the  nerve. 


282 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


The  following  three  incisions,  described  by  Stookey  and  Guild  (1919)  for 
exposure  of  the  musculospiral  nerve  from  the  lower  border  of  the  teres  major 
muscle  down  to  the  antecubital  fossa,  will  be  found  to  give  easy  access  to  the 
nerve. 

The  first  incision  is  along  a  line  from  the  posterior  angle  of  the  acromion  to 
the  tip  of  the  olecranon.  The  incision  should  begin  three  fingers  breadth  below 
the  acromion,  and  continue  directly  downward  along  the  above  line  to  5  cm. 


Fig.  no. — Line  of  incision  for  exposure  of  the  upper  third  of  the  musculospiral  nerve. 


below  the  level  of  the  insertion  of  the  deltoid,  and  should  be  carried  directly 
through  the  deep  fascia.  (See  Fig,  no.)  At  the  upper  angle  of  the  wound  the 
posterior  border  of  the  deltoid  and  the  long  and  outer  heads  of  the  triceps  can  be 
identified.  These  two  heads  of  the  triceps  are  separated  in  their  fascial  plane 
by  blunt  dissection.  The  deltoid  is  retracted.  If  necessary  a  small  part  of  the 
latter  muscle  may  be  cut.  The  separation  of  the  two  heads  of  the  triceps  is 
carried  down  to  the  lower  angle  of  the  wound,  following  as  closely  as  possible 
their  line  of  junction.  After  separating  the  muscle  fibers,  a  glistening  aponeuro- 
sis is  exposed;  this  is  incised  and  the  nerve  exposed  u]i  to  the  lower  border  of  the 


MUSCULOSPIRAI,    NERVE 


283 


tendon  of  the  teres  major  muscle.     The  exposure  thus  gained  is  excellent, 
and  little  damage  is  done  to  the  triceps  muscle. 

The  second  incision  runs  parallel  to  the  first  except  in  its  lower  part,  where 
it  is  slightly  curved  toward  the  anterior  side.  This  incision  should  begin  about 
12  cm.  above  the  antecubital  fossa,  lateral  to  the  brachialis,  and  between 
it  and  the  almost  longitudinal  fibers  of  the  supinator  longus.  The  usual  incision 
is  generally  not  sufficiently  vertical  and  lies  too  far  anterior — near  the  belly  of 
the  biceps.  If  this  second  incision  is  correctly  placed,  it  will  be  over  the  inter- 
space between  the  brachialis  and  the  supinator  longus,  where  the  lower  third 
of  the  musculospiral  nerve  is  to  be  found.  By  careful  dissection  the  nerve 
can  be  traced  into  the  antecubital  fossa  to  the  point  where  it  divides  into  the 
radial  and  posterior  interosseous  nerves. 


A 


Fig.  1 1 1. — E.xposure  of  the  musculospiral  nerve.     .1 ,  Line  of  incision  for  e.xposure  of  the  upper  two- 
thirds;  B,  line  of  incision  for  exposure  of  the  lower  two-thirds. 

By  these  two  incisions  exposure  of  the  musculospiral  nerve  in  its  upper 
and  lower  thirds  may  be  obtained.  By  blunt  dissection  the  nerve  is  followed 
in  the  fascial  space  beneath  the  triceps  and  through  the  lateral  intermuscular 
septum.  The  overlying  muscle  need  not  be  cut,  but  a  wide  tape  may  be  passed 
under  the  muscle  and  in  the  canal  through  which  the  nerve  can  be  followed. 
The  tape  is  then  clamped  above  the  muscle  and  the  muscle  retracted,  using  the 
tape  as  a  retractor.  (See  Fig.  113.)  With  this  retraction  the  nerve  may  be 
followed  through  from  the  dorsal  to  the  ventral  part  of  the  arm  and  sufficient 
exposure  gained  for  the  necessary  manipulations  of  the  nerve  without  further 
exposure.  Should  the  exposure  be  insufficient,  a  third  skin  incision  may  be 
made  midway  between  the  other  two  and  parallel  to  the  first;  it  extends  from 
3  cm.  above  the  level  of  the  insertion  of  the  deltoid  directly  downward  for 
abotit  12  cm.     The  incision  is  carried  through  the  triceps,  separating  the  fibers 


284 


SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 


longitudinally  until  the  aponeurosis  on  its  deep  surface  is  seen.     This  is  carefully 
incised  and  the  nerve  exposed  directly  beneath. 

If  one  of  the  incisions  above  described  does  not  give  suiificient  exposure 
several  of  them  may  be  combined  without  making  a  new  skin  incision  by 
connecting  them  in  an  oblicjue  or  curved  manner  and  undermining  the  skin 
edges.     (See  Figs,  in  and  112.)     By  connecting  the  two  skin  incisions  in  this 


LnXern')USC^Ai^ 
septum 

r<3LciiALi5 


Fig.  112. — E.xposure  of  musculospiral  nerve — lower  two-thirds.  Dotted  line  indicates  line  of 
incision  in  the  muscle.  The  sl^in  edges  are  undermined  and  retracted  so  as  to  connect  the  two 
incisions.     Note  that  the  incision  in  the  muscle  is  in  the  direction  of  the  muscle  fibers,  not  across  them. 


manner,  the  length  of  the  incision  will  be  shortened  and  the  skin  edges  may  more 
readily  be  retracted  out  of  the  field.  Additional  exposure  is  then  obtained  by 
carrying  the  incision  as  above  described;  longitudinally  through  the  deep 
structures.     (See  Fig.  113.) 

These  three  parallel  longitudinal  incisions  expose  the  musculospiral  nerve 
from  the  lower  border  of  the  teres  major  muscle  to  the  antecubital  fossa  with  the 
least  damage  to  the  overlying  tissues.     The  muscle  libers  when  separated  longi- 


MUSCULOSPIRAL    NERVE 


ludinall)'  are  damaged  but  little,  and  the  sensory  skin  supply,  frequently  com- 
pletely destroyed  by  the  spiral  incision,  is  in  a  great  measure  spared.  Thus,  the 
main  objections  to  a  sj)iral  incision  are  avoided  and  a  free  and  easy  exposure 
obtained. 


Fig.  113. — Exposure  of  musculospiral  nerve — lower  two-thirds.  Xote  the  retraction  of  the 
lateral  head  of  the  triceps  by  means  of  tape  and  clamp.  By  retraction  in  this  manner  bleeding 
is  stopped  and  an  excellent  exposure  gained. 


The  rather  vertical  course  of  the  musculospiral  nerve  is  not  appreciated 
from  the  name,  or  the  usual  anatomical  descriptions.  The  nerve  is  essentially 
vertical  in  its  upper  and  lower  thirds,  being  spiral  only  in  a  small  portion  of  its 
middle  third.  Perhaps  this  is  the  reason  why  a  spiral  incision  frequently  does 
not  lie  o\er  the  course  of  the  ncr\-e,  the  precise  position  of  which  is  difficult  to 
estimate. 

The  division  of  the  musculospiral  nerve  into  its  two  end  branches  may  take 
place  as  high  as  its  exit  through  the  lateral  intermuscular  septum,  in  which 
instance  the  posterior  interosseous  will  lie  lateral,  and  the  radial  nerve  medial. 


286 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


In  this  region  the  lateral  cutaneous  branch  of  the  musculocutaneous  nerve  will 
be  found  along  the  border  of  the  biceps  within  the  interspace  between  the 
brachialis  and  supinator  longus,  and  also  the  slender  muscular  branch  to  the 
extensor  carpi  radiahs  brexas,  which  has  a  long  extramuscular  course,  may  be 
destroyed  unless  its  position  be  recognized.     (See  Fig.  114.) 


Bre*.cKt.orad>i>-Us  ^ 


Branch  vaults  M. 


Br.tobi 


ira. 


Brito 
Ext  ca^rpL 
ravdta.Li.'s 
,longu5.  M. 


Exi.caLrpt 

rai.<ii.a.lL5-- 
longusM. 

Br.i.tQ  --/- 
brevts.M 
E3ci.c&.rpL 


Fig.  114. — Exposure  of  the  lower  third  of  the  musculospiral  nerve,  the  posterior  interosseous 
and  superficial  radial  nerves.  Note  the  long  extraneural  course  of  the  nerve  to  the  extensor  carpi 
radialis  brevis. 

Occasionally,  the  external  and  internal  cutaneous  nerves  within  the 
musculospiral  groove  may  be  nearly  as  large  as  the  main  nerve  trunk,  for  which, 
or  for  the  muscular  branches  of  which,  they  may  be  mistaken.  The  latter  do 
not  run  with  the  nerve  within  the  canal,  but  leave  it  to  pass  downward  into  the 
triceps,  while  the  cutaneous  branches,  if  traced,  will  be  found  to  pass  over  the 
intermuscular  septum.  It  is  possible  that  in  some  instances,  when  there  is 
considerable  loss  of  nerve  substance  and  scar,  the  main  nerve  trunk  and  the 


MUSCULOSPIRAL    NERVE 


287 


sensor}'  Ijranches  may  have  been  crossed  in  suture,  whicli  might  account  for 
some  cases  of  failure  and  absence  of  functional  regeneration. 

Posterior  Interosseous  Nerve. — To  expose  this  nerve,  the  arm  is  slightly 
flexed  across  the  lower  abdomen  with  the  hand  semipronated.  The  prominence 
of  the  lateral  condyle  and  the  radial  border  of  the  extensor  digitorum  communis 
are  identified.     By  rapidly  moving  the  fingers  passively,  without  extension 


E/xt,  Condyle 


rjst   i.fitero^5«ou3  M 


3up^^A.fcor  H.  spiii 


dioii 


(lit    ccmmun'i 


Fig.  115. — E.xposure  of  the  posterior  interosseous  nerve.  The  supinator  muscle  is  split  in  the 
direction  of  its  fibers  to  locate  the  posterior  interosseous  nerve.  (Stookey  and  Guild,  Surg.,  Gyn.  and 
Obst.,  igig.) 

of  the  wrist,  the  common  extensor  may  be  recognized.  Lateral  to  it  lie  the 
extensor  carpi  radialis  longus  and  brevis.  An  incision  12  cm.  long  is  carried 
from  the  lateral  condyle  directly  downward  along  the  line  between  the  extensor 
digitorum  communis  and  the  extensor  carpi  radialis  longus  and  brevis,  through 
the  deep  fascia.  Beginning  at  the  lower  angle  of  the  wound,  the  interspace 
between  these  muscles  is  identified  and  they  are  separated  by  blunt  dissection  as 
far  as  their  common  origin.     Here  the  muscle  fibers  are  cut  longitudinally  up 


288 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


to  the  lateral  condyle.  This  last  step  is  essential  in  order  to  obtain  adequate 
exposure.  The  muscles  are  then  widely  retracted  and  the  common  extensor 
aponeurosis  on  the  deep  surface  of  the  muscle  mass  exposed.  Its  free  medial 
border  can  be  readily  found,  then  freed  by  blunt  dissection  and  retracted  with 
the  extensores  carpi  radialis,  thus  exposing  the  obliquely  running  fibers  of  the 


J  _  P    r  a  t  or  M    C  ui 


Qdductp 

Ext  f>oUiai  brev 


T^,  Cut  <iiqlt.ayr\mu 
CiLrp.uLn^ris 


Fig.  ii6. — Exposure  of  the  posterior  iiiterosscjus  nerve.  The  nerve  having  been  located  by 
splitting  the  supinator  muscle,  the  muscle  is  then  cut  exposing  the  nerve.  (Stookey  and  Guild, 
Surg.,  Gyn.  and  Obst.,  igig.) 

supinator  brevis.  These  fibers  run  forward  and  downward  toward  the  flexor 
surface  of  the  forearm.  The  posterior  interosseous  nerve  is  within  or  beneath 
this  muscle.  The  nerve  runs  almost  at  right  angles  to  the  muscle  fibers,  diago- 
nally across  the  radius  toward  the  extensor  surface.  At  a  point  two  fingers 
breadth  below  the  condyle,  the  fibers  of  the  supinator  brevis  are  separated  in 
the  direction  of  their  course  by  blunt  dissection,  using  two  tissue  forceps.  In 
the  opening  thus  made,  the  flat  posterior  interosseous  nerve  will  be  seen. 
(See  Fig.  115.) 


MUSCULOSPIRAL    NERVE 


289 


Having  thus  found  the  exact  position  of  the  nerve,  the  supinator  brevis  is 
cut  across  or  retracted  in  the  line  of  the  nerve,  thus  exposing  it  freely  in  the  main 
portion  of  its  course,  without  danger  of  injury.  (See  Fig.  116.)  Without  the 
part  separation  of  the  muscle  fibers  by  blunt  dissection  at  right  angles  to  the 
nerve,  difficulty  may  be  encountered  in  finding  it.  Should  it  become  necessary 
to  expose  the  posterior  interosseous  nerve  higher  than  this  incision  permits,  the 
lower  incision  described  above  for  the  musculospiral  nerve  should  also  be  made. 


rlgsculo-spwa-t 


"teoaon 


Fig.  ii;. — Trunipoiilion  of  the  musculospiral  nerve.  The  central  end  of  the  musculospiral 
nerve  is  exposed  as  it  crosses  the  tendon  of  the  latissimus  dorsi  and  followed  down  into  the  scar  and 
callus  on  the  dorsum  of  the  humerus.  (See  Fig.  ii8.)  .\  silk  suture  has  been  passed  through  the  scar 
on  the  nerve  and  the  central  end  of  the  nerve  withdrawn  so  as  to  lie  on  the  medial  surface  of  the  arm. 
A  second  silk  suture  has  been  passed  through  the  scar  on  the  distal  end  and  this  passed  to  the  medial 
surface  of  the  arm  beneath  the  biceps.     By  this  transposition  end-to-end  suture  can  be  accomplished. 

Transposition  of  the  Musculospiral  Nerve. — Transposition  of  the  musculo- 
spiral nerve  from  its  position  behind  the  humerus  to  in  front  may  be  done  in 
extensive  injury  of  the  nerve  in  its  middle  third.  (See  Fig.  117.)  The  nerve  is 
exposed  above,  in  the  lower  part  of  the  axilla  as  has  already  been  described,  care 
being  taken  to  safeguard  the  motor  branches  to  the  triceps  which  are  given  off 
at  this  level.     (See  p.  280.) 

The  nerve  is  then  exposed  in  its  lower  third,  beginning  below  in  the  anti- 
cubital  fossa  and  working  upward,  following  the  nerve  beneath  the  lateral  head 
of  the  triceps  as  shown  in  Fig.  113.  The  nerve  is  then  freed  from  the  surround- 
ing scar  or  callus  in  its  middle  third.     If  the  injur}-  to  the  nerve  is  extensive  (see 


290 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Fig.  118)  and  end-to-end  suture  cannot  be  accomplished,  or  particularly  if  a 

suitable  nerve  bed  cannot  be  made,  transposition  of  the  nerve  may  then  be  done. 

The  nerve  is  severed  in  its  scar,  leaving  scar  tissue  on  both  the  central  and 

distal  ends  so  that  freshened  nerve  ends  may  not  be  traumatized  in  the  manipu- 


FiG.  118. — Transposition  of  llie  musculospiral  nerve  (same  as  Fig.  117).  Musculospiral  nerve 
caught  in  caUus  in  its  upper  and  middle  thirds.  Damage  to  the  nerve  too  extensive  to  permit  end- 
to-end  suture  without  transposition. 

lations  necessary  to  bring  the  nerve  to  the  medial  side  of  the  arm.  A  silk 
stay  suture  is  passed  through  the  central  end  and  the  suture  grasped  with 
forceps  and  passed  back  along  the  course  which  the  nerve  has  taken  to  gain  the 
dorsum  of  the  humerus.  The  nerve  is  made  to  appear  in  the  opening  at  the 
inner  head  of  the  triceps  where  it  entered  the  musculospiral  groove.     The 


MUSCULOSPIRAL    NERVE  29 1 

motor  branches  given  off  just  below  the  tendon  of  the  latissimus  dorsi  are 
kept  in  view  so  that  they  may  not  be  injured.  If  need  be,  these  branches  can 
be  separated  from  the  nerve  trunk  separately  for  a  short  distance  in  order 
to  allow  freer  mobilization  of  the  central  end  and  to  avoid  sharp  angles.  The 
distal  end  of  the  nerve  is  now  passed  in  like  manner  in  front  of  the  humerus 
in  a  tunnel  made  beneath  the  brachialis  muscle,  or  the  nerve  may  be  passed 
superficial  to  this  muscle  and  beneath  the  biceps. 

After  both  the  central  and  distal  ends  have  thus  been  transposed,  the  arm 
may  be  flexed  and  adducted  in  order  to  allow  end-to-end  suture.  By  traction 
on  the  silk  stay  sutures  the  scar  tissue  on  the  nerve  ends  are  approximated  and 
the  point  at  which  excision  of  scar  is  to  be  made  determined.  Thus  fresh, 
untraumatized  nerve  ends  are  presented  for  suture. 

This  method  of  transposition  is  of  value  in  selected  cases  only.  If  the 
motor  supply-  to  the  triceps  be  endangered  by  transposition,  as  may  be  the  case 
in  injury  to  the  nerve  at  certain  levels,  transposition  should  not  be  attempted 
since  extension  of  the  forearm  is  more  important  than  extension  of  the  wrist  and 
fingers  for  the  latter  movements  may  be  obtained  by  tendon  transplantation. 
If  neither  transposition,  can  be  done,  nor  regeneration  obtained  by  nerve  graft 
tendon  transplantation  of  the  palmaris  longus,  flexor  carpi  radialis  or  pronator 
teres  will  give  fairly  good  functional  extension  of  the  wrist  and  fingers  as  well  as 
of  the  thumb,  and  in  selected  cases  is  a  method  of  choice. 

Comment. — Regeneration  following  suture  of  the  musculospiral  nerve  has 
been  more  complete  than  in  any  other.  This  may  be  due  to  the  fact  that  there 
are  relatively  fewer  cutaneous  sensory  and  sympathetic  fibers  in  the  main 
nerve  trunk  than  in  the  median  and  ulnar  nerves,  and  since  the  funiculi  of  the 
musculospiral  nerve,  are  relatively  large  and  few  in  number,  funicular  cross- 
ing is  less  apt  to  occur,  hence  more  accurate  funicular  apposition  may  be 
obtained.  Again,  motor  return  may  be  relatively  imperfect,  yet  functionally 
satisfactory,  since  the  muscles  supjilicd  generally  do  not  partake  in  finer 
movements  which  require  not  only  motor  impulses  but  accuracy  in  the 
proprioceptive  impulses,  and  also  reflex  co-ordination  of  the  associated  syner- 
gic units.  The  failure  to  re-establish  jiroprioceptive  sensation  or  its  partial 
loss  would  be  much  more  noticeable,  for  example,  in  the  ulnar  nerve.  Yet 
Stopford  (1920)  has  called  attention  to  the  fact  that  even  in  musculospiral 
nerve  injuries,  in  which  regeneration  has  taken  place,  "the  grasp  is  extremely 
weak,  owing  to  the  loss  of  the  svnergic  extension  of  the  wrist." 


292       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

The  course  of  regeneration  in  the  musculospiral  nerve  is  similar  to  that 
in  all  nerves,  namely,  the  first  muscles  to  recover  are  those  whose  branches  lie 
closest  to  the  site  of  suture,  and  recovery  in  each  muscle  is  in  sequence,  according 
to  the  order  in  which  the  branches  arise  from  the  nerve.  The  last  muscles  to 
recover  are  the  extensor  muscles  of  the  thumb,  especially  the  extensor  poUicis 
brevis.  This  retarded  recovery  may  also  be  due  to  the  fact  that  most  splints 
have  corrected  overstretching  of  the  extensors  of  the  wrist  and  fingers,  but  have 
neglected  the  extensors  of  the  thumb  and  have  permitted  this  digit  to  hang 
without  support.  Consequently,  these  muscles  are  overstretched,  and  while 
function  returns  in  the  extensors  of  the  fingers  none  appears  in  the  thumb. 
In  most  such  instances  return  of  function  in  the  extensors  of  the  thumb  has 
followed  continued  relaxation  of  these  muscles  by  simple  mechanical  means. 
Of  all  the  muscles  supplied  by  the  musculospiral  nerve  these  muscles  are  the 
most  distal,  a  point  which  may  influence  their  chances  of  re-innervation. 
(See  Charts  Vni-XI.) 

In  addition,  the  percentage  of  regeneration  of  the  extensor  brevis  pollicis 
as  given  by  Stopford,  shows  16%  recoveries  in  suture  in  the  lower  third  of  the 
arm,  17%  in  the  middle  third  and  27%  in  the  upper  third,  which,  he  suggests 
EXPLANATIONS  OF  CHARTS  VIII  TO  XI 

The  vertical  columns  i  to  24  refer  to  the  months  after  the  performance 
of  the  suture;  in  the  last  column,  "delay,"  reference  is  made  to  any  case  where 
an  interval  of  eighteen  months  or  more  has  occurred  between  the  date  of  the 
reception  of  the  wound  and  the  time  of  the  operation;  the  figures  express  this 
interval  in  months.  In  all  the  charts  reference  is  made,  unless  otherwise 
stated,  to  the  return  of  voluntary  power,  since  in  my  experience  this  has  been 
more  frequently  discovered  at  an  earlier  date  than  the  recovery  of  faradic 
response.  The  muscles  are  recorded  by  means  of  the  initial  letters,  viz. : 
SL — supinator  longus. 

As  regards  sensation,  information  is  conveyed  by  the  following  abbrevia- 
tions and  letters: 

P.,  commencement  of  recovery  of  protopathic  sensibility. 

P.  rec,  complete  recovery  of  protopathic  sensibility. 

E.  commencement  of  recovery  of  epicritic  sensibility. 

The  interrupted  hnes  in  certain  columns  mark  the  date  of  the  last  examina- 
tion, unless  they  occur  in  the  last  column,  in  which  case  several  of  the  patients 
have  been  under  observation  for  further  periods,  but  the  intervals  between  the 
later  examination  have  been  longer  than  four  to  six  weeks. 


MUSCULOSPIRAL   NERVE 


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296       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


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Lower  third  (twenty-five  cases) 


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Chart  XI 
Upper  third  (seven  cases) 
To  Show  Date  of  Recovery  of  VoLrxiARY  Power  of  the  Various  Miscles  at  the 

Three  Levels 

(SropFORD,  Proc.  Roy.  Soc.  of  Med.,  vol.  13:  1919-1920).     For  explanation  of  Chart  XI.  see  p.  292. 

may  be  additional  evidence  of  the  influence  of  the  site  of  the  lesion  in  relation 
to  the  ventral  column  cells.  The  more  distant  the  suture  from  a  nerve  branch 
supplying  a  muscle  the  less  likely  is  there  to  be  any  permanent  dispersion  of 
neuraxes  destined  to  a  given  branch  due  to  the  internal  plexuses  within  the 


CIRCUMFLEX   NERVE 


297 


nerve  trunk  and  the  rearrangement  which  may  take  place  in  them.  Further- 
more, in  large  muscles,  a  number  of  nerve  libers  may  be  lost  without  gross 
functional  impairment.  The  extensor  pollicis  brevis  is  a  comparatively  small 
muscle,  having  proportionately  few  fibers  and,  therefore,  a  loss  of  only  a  few 
fibers  would  be  more  apt  to  produce  marked  functional  loss. 

CIRCUMFLEX  NERVE 

This  nerve  arises  from  the  dorsal  cord  of  the  brachial  plexus  and  is  made 
up  of  fibers  from  the  dorsal  divisions  of  the  fifth  and  sixth  cervical  nerves  and 
supplies  primitive  dorsal  musculature — the  deltoid  and  teres  minor  muscles, 
as  well  as  the  shoulder-joint  and  the  skin  over  the  deltoid. 


Fig.  iig. — Right  deltoid  muscle,  nerve  distribution  projected  upon  the  superficial  surface.     (Frohse 

and  Frankel.) 

Course. — Within  the  axilla  the  nerve  runs  in  the  sheath  of  the  musculo- 
spinal nerve  lying  along  its  lateral  border.  The  circumflex  leaves  the  main 
nerve  trunk  at  the  outer  border  of  the  subscapularis  muscle  and  passes  with  the 
posterior  circumflex  artery  and  vein,  the  vessels  lying  above  the  nerve,  through 


20S   SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERIPHERAL  NERVES 

the  quadrilateral  space  formed  by  the  teres  minor  and  subscapularis  above,  the 
latissimus  dorsi  below,  the  long  head  of  the  biceps  laterally  and  the  humerus 
medially.  The  nerve  lies  under  cover  of  the  deltoid  as  it  winds  around  the 
surgical  neck  of  the  humerus  from  behind  forward. 

Branches. — The  nerve  really  consists  of  two  main  bundles,  the  larger  fun- 
iculus lying  mecHal  and  the  smaller  lateral.  The  medial  supplies  theteres minor 
and  a  part  of  the  spinal  portion  of  the  deltoid,  while  most  of  its  libers  form  the 


Fig.  1 20. — E.Kposure  of  the  insertion  of  the  pectoralis  major  muscle  with  disinsertion  and  resu- 
ture.  Dotted  line  indicates  incision  in  the  periosteum..  The  periosteum  is  then  pushed  back  and  a 
ridge  of  bone  together  with  the  insertion  of  the  pectoralis  major  is  removed.  The  insert  on  the 
right  shows  the  ridge  of  bone  and  pectoralis  insertion  removed,  that  on  the  left,  the  bone  and  tendon 
replaced  and  the  tendon  and  periosteum  sutured. 

cutaneous  branch  of  the  circumflex.  The  lateral  bundle  gives  oft'  the  articular 
branch  to  the  shoulder  joint  and  supplies  the  remaining  portions  of  the  deltoid. 
(See  Fig.  119.) 

Exposure.  In  the  Axilla. — The  arm  is  held  in  extreme  abduction  and  out- 
ward rotation.  A  sand  bag  is  placed  beneath  the  shoulder  near  the  midline  so 
as  to  leave  the  lateral  portion  of  the  shoulder  free.  An  incision  20  cm.  long 
is  made  in  the  line  of  the  great  vessels  with  its  middle  over  the  proximal  border 
of  the  latissimus  dorsi  tendon.     The  incision  is  then  carried  through  the  deep 


CIECUMFLEX   NERVE  299 

fascia,  and  the  pectoralis  major  is  retracted  upward.  In  exposure  of  the  nerve 
higher  up  this  muscle  obstructs  the  field  and  should  be  cut  at  its  insertion  rather 
than  through  the  muscle  fibers.  (See  Fig.  120.)  The  neurovascular  bundle 
is  then  exposed  from  below  up,  and  the  circumflex  nerve  may  be  found  by  follow- 
ing up  along  the  musculospiral  nerve  to  the  origin  of  the  circumflex  from  this 
nerve.  The  circumflex  arises  at  a  point  corresponding  to  the  junction  of  the  mid- 
dle and  outer  thirds  of  the  axillary  artery,  and  usually  from  the  medial  side  of  the 
musculospiral  nerve,  though  it  may  occasionally  arise  from  the  lateral  side. 
The  nerve  may  be  sought  as  it  enters  the  quadrilateral  space  just  above  the 
latissimus  dorsi  tendon,  using  the  latter  as  a  guide  to  the  nerve,  which  lies  close 
to  the  medial  border  of  the  tendon.  Once  the  nerve  is  identified  it  can  be 
traced  downward  behind  the  vessels  of  the  axilla. 

Exposure  at  the  Surgical  Neck. — If  the  nerve  has  been  injured  more  distally 
it  may  be  exposed  where  it  passes  around  the  surgical  neck  of  the  humerus. 
The  arm  is  placed  in  the  same  position  as  for  exposure  of  the  upper  third  of  the 
musculospiral  nerve.  (See  Fig.  no.)  A  longitudinal  incision  12  cm.  long  is 
made  along  the  dorsal  border  of  the  deltoid.  This  muscle  is  retracted  upward, 
or  its  most  dorsal  fibers  may  be  spHt  from  the  rest  of  the  muscle  and  the  nerve 
sought  against  the  humerus  as  it  makes  its  exit  from  the  cjuadrilateral  space  to 
wind  around  the  surgical  neck. 

If  the  nerve  is  injured  where  it  is  about  to  break  up  into  its  terminal 
branches,  suture  may  not  be  possible  and  direct  implantation  of  the  central 
stump  into  the  muscle  should  be  done.     (See  Chapter  IV.) 

Deformity.—  Due  to  paralysis  of  the  deltoid  the  arm  cannot  be  abducted 
but  slight  elevation  may  be  accomplished  by  the  supraspinatus.  (Seepage  2 29.) 
In  certain  instances  elevation  may  be  accomplished  by  the  patient  lowering 
his  shoulder  and  contracting  his  biceps,  thus  fixing  the  shoulder-joint  and,  by  a 
swinging  motion  of  the  trunk,  bring  the  humerus  to  such  a  position  that 
elevation  may  be  accomplished  by  the  clavicular  head  of  the  pectoralis  major, 
the  coracobrachialis  and  the  biceps.  Such  attempts  at  elevation  are  awkward 
and  the  mechanism  quite  obvious.  In  this  manner  the  patient  uses  muscles 
which  normally  participate  in  elevation  of  the  arm  though  their  role  is  ordinarly 
a  minor  one. 

In  circumflex  paralysis  the  shoulder  is  flattened  and  the  humerus  falls-away 
so  that  a  space  intervenes  between  the  head  of  the  humerus  and  the  acromion. 
The  arm  is  held  in  adduction  by  the  pectoralis  major,  latissimus  dorsi  and  sub- 
scapularis  muscles.     Both  the  acromion  and  coracoid  processes  are  prominent. 


300       SURGICAL    AND     MECHAXICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Mechanical  Treatment. — The  arm  should  be  abducted  to  ninety  or  a  hundred 
degrees.  The  foreman  may  be  flexed  and  held  horizontal  so  that  the  patient 
may  make  use  of  his  hand.  To  accomplish  this  an  airplane  splint  is  light  and 
satisfactory.  (See  Fig.  98.)  However,  the  patient  frequently  objects  to 
the  awkward  position  in  which  the  arm  is  thus  held.  If  this  position  is  refused 
the  arm  may  be  placed  in  a  sling  and  an  extra  sling  passed  around  the  elbow  and 
over  the  acromion  and  tightened.  Thus  by  drawing  the  humerus  upward  and 
lessening  the  distance  between  the  head  of  the  humerus  and  the  acromion  the 
deltoid  is  relaxed  and  its  overstretching  by  dragging  down  of  the  arm  is 
prevented. 

REFERENCES 

AcHARD,  H.  P.   and  Jarkowski,  J.:  La  transplantation  tendeneuse  conime  traitement  de  la 

paralysie  radiale,  Progres  med.,  Sept.,  1920,  pp.  3S7-390. 
Andre-Thoii.\s:  Reactions  pilomotrices   dans   la  paralysie  du  nerf  radial,  Rev.  Neurol., 

V.  35:  (v.  26),  1919.  pp.  448-450. 
ANSESfN,  Otto:  Fascien-implantation  bei  Radialis- und  Peroneuslahmung,   Beitr.   z.  klin. 

Chir.,  V.  105:  1917,  pp.  587-593. 
Auvray:  Resultats  eloignes  de  39  plaies  du  nerf  radial  operees  in  191 5  and  1916.,  Bull,  et 

mem.  Soc.  de  chir.  de  Par.,  v.  45:   1919,  p.  1291. 
Baisch:  Zur  Frage  der  Sehnenoperationen  bei  irreparabler   Radialislahmung,   Munchen. 

med.  Wchnschr.,  v.  66:  1919,  p.  835. 
BoRCHARDT,  jM.  and  Wj.'^sxiexski:  Der  Nervus  Radialis,  Bruns  Beitrage  z.  klin.   Chir., 

V.  117:  1919,  p.  475- 
Deus,  p.:  Zur  Fruhoperation  der  Nervenverletzungen,  Munchen.  med.  Wchnschr.,  v.  64: 

1917,  p.  1252. 
DuxN,  N.:  Treatment  of  lesions  of  the  musculospiral  nerve  in  military  surgery,  Am.  J. 

Orthop.  Surg.,  v.  16:   1918,  p.  25S. 
Fkohse,  F.  and  Fr-^nkel,  M.:  Die  Muskeln  des  menschlichen  Amies,  Jena,  1908,  G.  Fischer. 
Harris,  W.:  The  true  form  of  the  brachial  plexus,  and  its  motor  distribution;  J.  Anat.  & 

Physiol.,  V.  38:  1903-04,  p.  399. 
Hass,  J.:  Zur  Sehnenoperation  bei  Radialslahmung,  Beitr.  z.  klin.  Chir.,  v.  116:   1919,  pp. 

690-704. 
Jarkowski,  J.  and  Ach.\rd,  H.  P.:  Transplantations  tendineuses  dans  la  paralysie  radiale 

traumatique;  Presentation  d'un  cas.  Rev.  Xeurol.  v.  35:  (X.  S.  26),  1919,  pp.  2S3-2S7. 
Krause,   W.:  Beitrage  zur  systematischen  Neurologic  des  menschlichen  Armes,  Arch.  f. 

Anat.,  Physiol,  u.  wissensch.  Med.,  1864,  p.  349. 
Marie,   P.,   Meige,  H.   and  Patrikoos:  Paralysie  radiale  dissociee  simulant  une  grifite 

cubitale,  Rev.  Neurol.,  V.  24:  Feb.  and  March,  i9i7,p.  123. 
Marie,  P.,  Cosset,  A.  and  Meige,  H.:  Les  Localisations  motrices  dans  les  nerfs  periph- 

eriques.  Bull,  de  r.\cad.  de  med.  Par.,  v.  74:   1915,  p.  798,  (Ser.  3). 


CIRCUMFLEX    NERVE  30I 

Massart,  R.:  Le  traitement  chirurgical  de  la  paralysie  radiale  traumatique  par  la  trans- 
plantation tendineuse,  These  de  Paris,  191S. 
Mauclaire,  p.:  A  propros  des  resultats  elognes  des  plaies  des  nerfs,  Bull,  et  mem.  Soc. 

de  chir.  de  Par.,  v.  45:   igig,  p.  1344. 
Perthes,  G.:  Schussverletzungen  peripherer  Nerven  (XVH  Wanderversammlung  der  Siid- 

wetsdeutschen  Neurologen  und  Psychiater  in  Baden-Baden,  2  und  3  Juni,  1917),  Mun- 

chen.  med.  Wchnschr.,  v.  31:   1917. 
Ueber   Sehnenoperationen    bei    irreparabler   Radialislahmung,    nebst    Studien   iibcr    die 

Sehnenverpflanzung  und  Tenodese  im  allgemeinen,  Beitr.  z.  klin.  Chir.,  v.  113:   1918, 

pp.  2S9-368. 
RouSEY,  G.  and  Braxche,  J.:  Deu.x  cas  de  paralysies  dissociees  de  la  branche  posterieure 

du  radial  a  type  de  pseudo-griffe  cubitale.  Rev.  Xeurol.,  v.  24:  No.  2,  Nov.  and  Dec. 

1917,  p.  312. 

Spitzy,  H.:  Operative  Behebungen  Liihmung  des  N.  RadiaKs,  Arch.  f.  Psychiat.,  v.  59: 

igiS,  p.  652. 
Stern,  K.:  Schussverletzungen  des  Nerves  radialis,  Deutsch.  mil-artzl.  Ztschr.,  v.  46:  1917, 

P-  ^ii- 
Stopford,  J.  S.  B.:  The  results  of  secondary  suture  of  peripheral  nerves.  Brain,  v.  43:  pt.  i, 

1920,  p.  I. 
Stookey,  B.  and  Guild,  S.:  A  method  of  exposing  the  musculospiral  and  the  posterior 

interosseous  nerves,  Surg.,  Gynec.  &  Obst.,  June,  1919,  pp.  612-615. 
SuDECK,  F.:  Zur  Sehnentransplantation  bei  der  Radialislahmung,  Deutsch.  med.  Wchnschr., 

V.  45:   1919,  p.  1000. 


CHAPTER  XIII 
MUSCULOCUTANEOUS  NERVE 

Anatomy. — The  musculocutaneous  nerve  arises  from  the  ventral  division 
of  the  fifth  and  sixth  cervical  nerves  and  is  joined  by  the  nerve  to  the  coraco- 
brachialis  which  arises  from  the  seventh  cervical.  This  latter  nerve  may  be 
entirely  separate  from  the  musculocutaneous  or  it  maybe  completely  incorpo- 
rated within  the  sheath  of  the  latter.  Through  these  two  nerves  the  coraco- 
brachialis  muscle,  biceps  and  brachialisa  re  supplied;  the  brachialis  occasional^ 
receiving  a  twig  also  from  the  musculospiral  nerve.  The  coracobrachialis 
and  biceps  develop  entirely  from  primitive  ventral  musculature  and  conse- 
quently are  supphed  solely  by  ventral  branches,  whereas,  as  has  been  said, 
the  brachialis  is  a  composite  muscle  formed  by  fusion  of  both  ventral  and  dorsal 
musculature. 

Course. — The  musculocutaneous  nerve  separates  from  the  outer  cord 
of  the  brachial  plexus  generally  at  a  point  beneath  the  pectoralis  minor  muscle, 
though  it  may  separate  more  peripherally,  almost  as  a  branch,  from  the  median 
nerve.  The  nerve  lies  at  first  between  the  axillary  artery  and  the  coraco- 
brachialis muscle,  but  almost  immediately  pierces  this  muscle  between  its 
two  heads  of  origin  and  then  descends  between  the  biceps  muscle  and  the 
brachialis.  It  emerges  from  under  the  biceps,  pierces  the  deep  fascia  just 
above  the  elbow  along  the  lateral  border  of  the  biceps  and  terminates  in  cut- 
aneous branches  for  the  supply  of  the  outer  side  of  the  forearm.     (See  Fig. 

121.) 

Branches. — A  branch  to  the  coracobrachialis  arises  just  before  the  nerve 
pierces  this  muscle.  The  branch  to  both  heads  of  the  biceps  is  given  off  at 
about  the  junction  of  the  middle  and  upper  thirds  of  the  muscle  and  the  bran- 
ches to  the  brachialis  at  a  somewhat  lower  level.  (See  Fig.  12  2.)  Occasionally 
two  sets  of  branches  to  this  latter  muscle  are  found,  consisting  of  an  upper  and 
lower  group.  The  terminal  branches  of  the  musculocutaneous  are  cutaneous, 
which  pierce  the  deep  fascia  slightly  above  the  elbow  medial  to  the  cephalic 
vein  and  descend  along  the  radial  side  of  the  forearm  as  far  as  the  ball  of  the 

thumb. 

302 


MI^SCULOCUTANEOUS    NERVE 


303 


The  nerve  for  the  coracobrachialis  may  be  completely  separate,  as  a  distinct 
bundle  lying  on  the  lateral  border  of  the  nerve.  Adjacent  to  this  bundle  lies  the 
funiculus  for   the  biceps,   while  on   the  medial  border  is  the  funiculus  for 


Fig.   121. — Musculocutaneous  nerve.     Surface   projection,     i,   Musculocutaneous;   2,   branch 
to  coracobrachialis;  3,  branch  to  biceps  (both  heads);  4,  branch  to  brachialis;  5,  cutaneous  branch. 

ihc  brachialis.     Between  the  funiculi  for  the  biceps  and  the  brachialis  are  the 
sensory  funiculi  of  the  nerve  which  terminate  in  the  sensory  branches. 

Anomalies. — Abnormalities   in  the  distribution  of  the  musculocutaneous 
and  median  nerves  are  important  since,  in  these  anomalies,  may  be  found  the 


304   SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERIPHERAL  NERVES 


_M.  biceps,  caput  longum 


N.  musculocutaneus 


M.  coracobrachiali; 


N.  medianus 


M    biceps,  caput 
tertium 


R    collateralis  n. 
mediani 


N.  cutaneus  ante- 
brachii  lateralis 


—    R.  articularis  cubiti 


Fig.  122. — Nerve  distribution  to  the  flexor  muscles  in  the  arm.      (Frohse  and  Frankel.) 


MUSCULOCUTANEOUS    NERVE  305 

explanation  of  some  unusual  and  otlierwise  puzzling  jjaralyscs.  In  no  other 
two  nerves  of  the  extremity  are  the  variations  in  distribution  more  frequent  or 
more  numerous.  The  explanation  of  these  variations  is  found  in  the  compara- 
tive anatomy  and  development  of  the  musculocutaneous  and  median  nerves. 
Both  nerves  supply  primitive  ventral  musculature.  In  man,  the  outer  cord  of 
the  brachial  plexus  gives  rise  to  the  musculocutaneous  and  part  of  the  median; 
both  nerves  receive,  in  part  at  least,  libers  from  the  more  cephalic  of  the  spinal 
segments  forming  the  brachial  plexus. 

The  musculocutaneous  and  median  nerves  of  some  vertebrates,  such  as  the 
ruminants,  constitute  a  single  nerve  trunk.  In  higher  mammals  a  division 
of  this  single  nerve  trunk  into  two  separate  nerves  occurs.  At  first  the  musculo- 
cutaneous appears  as  a  branch,  not  of  the  outer  cord  of  the  plexus,  but  of  the 
median  nerve.  Some  of  the  earlier  anatomists  (Arnold,  185 1  Hyrtl,  1851) 
considered  the  musculocutaneous  as  a  branch  of  the  median  nerve.  Not 
infrequently  the  musculocutaneous  does  arise  as  a  branch  of  the  median,  but 
such  origin  is  unusual. 

Various  abnormalities  in  distribution  have  been  described  by  Gruber 
(1849)  Hytrl  (1859),  Gegenbaur  (1867),  Krause  (1868).  The  median  nerve 
may  give  off  the  cutaneous  branch  which  should  arise  from  the  musculocutan- 
eous, or  it  may  supply  muscular  branches  to  the  biceps,  and  even  to  the  brachi- 
alis.  The  whole  motor  and  sensory  distribution  of  the  musculocutaneous  nerve 
may  be  taken  over  completely  by  the  median.  On  the  other  hand,  the  muscul- 
cutaneous  may  take  over  partly,  or  completely,  the  motor  and  sensory  distri- 
bution of  the  median,  but  this  latter  type  of  variation  is  rarer.  The  rarity 
of  this  type  is  to  be  expected  since  the  musculocutaneous  in  its  development 
represents  a  migration  of  fibers  to  it  from  the  primitive  median  nerve  trunk. 

Some  form  of  communication  between  these  two  nerves  is  found  in  70% 
according  to  Gegenbaur.  A  few  of  the  different  forms  of  these  variations  are 
shown  schematically.  (See  Figs.  123  and  124.)  A  study  of  these  will  help  to 
make  clear  the  different  abnormalities  and  variations  in  the  distribution  of  these 
two  nerves. 

The  extent  of  the  communication  between  these  two  nerves  may  also  vary 
somewhat  according  to  the  type  of  plexus.  The  fibers  pass  from  the  musculo- 
cutaneous to  the  median  nerve  more  often  in  the  postfixed  plexus  than  in  the 
prelixed,  possibly  due  to  the  fact  that  in  the  postfixed  plexus  the  contri- 
bution of  the  fifth  and  sixth  cervical  roots  to  the  median  nerve  is  less  than 

in   the  prelixed.     Consequently  in   a  median   nerve  arising  from  the  latter 
20 


306       SURGICAL    AND    MECHANICAL    TREATMENT     OF    PERIPHERAL    NERVES 


'  B^    to  Corico  Br^ch.M 


Ir.ner'   Cord  . 


Fig.  123. — Schematic  drawing  showing  abnormalities  in  the  distribution  of  the  median  and 
musculocutaneous  nerves.  ^-1,  Types  of  communications  between  the  median  and  musculocutaneous 
nerves.  The  direction  of  the  fibers  in  a,  a'  and  a"  may  be  from  the  median  to  the  musculocutaneous, 
or  from  the  musculocutaneous  to  the  median  and  may  occur  at  any  level  in  the  arm;  B,  the  communi- 
cation a  is  given  off  from  the  musculocutaneous;  part  of  this  joins  the  median  and  the  rest  rejoins  the 
musculocutaneous  at  a  lower  level;  C,  the  nerve  supply  of  the  cutaneous  distribution  of  the  musculo- 
cutaneous is  taken  over  by  the  median,  the  musculocutaneous  in  this  instance  being  a  purely  muscular 
nerve. 


MUSCULOCUTANEOUS   NERVE 
/ 


307 


Inn»r  Cord- 

Fio.  124. — Schematic  drawing  showing  abnormalities  in  the  distrilmtion  of  the  median  and 
musculocutaneous  nerves.  A,  The  muscular  branch  to  the  coracobrachialis  is  given  off  directly 
from  the  outer  cord  of  the  plexus.  The  musculocutaneous  nerve  a  is  little  more  than  a  communication 
to  the  median.  The  latter  nerve  gives  o£E  the  muscular  branch  to  the  biceps,  brachialis  and  the 
cutaneous  branch  normally  from  the  musculocutaneous  nerve;  B,  the  entire  distribution  of  the 
musculocutaneous  nerve  is  supplied  through  the  median;  C,  the  major  distribution  of  the  median 
nerve  is  supplied  through  the  musculocutaneous  nerve. 


308      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Median  N  Uft 


Commnnicat  ion 

to  f  llTl.lCU.Lu«  of 

pi-otia-tortfffes- 
6  flex  ca.rpi 
radiAlis 


1  .- 


Elba 


MusciiIdc 


ta.usDU5  br- 


Ultxa^r  boT(3er 


MusculocutanrousN  typc  there  is  asecondary  reinforcement  of  its  fifth 
cervical  component  by  an  additional  contribution 
from  the  musculocutaneous.  Conversely,  in  the 
prefixed  variety  the  direction  of  the  communica- 
tion may  be  reversed  and  a  reinforcement  from 
the  median  nerve  be  sent  to  the  musculocutaneous. 
In  some  instances  by  finer  dissections  the  com- 
munication of  the  musculocutaneous  to  the  median 
(see  Fig.  125)  has  been  shown  to  consist  of  three 
funiculi.  The  first  passes  to  the  median  nerve, 
and  runs  in  the  median  for  a  short  distance,  to  re- 
turn again  to  the  musculocutaneous.  The  second 
enters  the  funiculus  destined  to  the  pronator  teres 
and  flexor  carpi  radialis,  and  has  been  traced  as 
far  as  the  humeral  head  of  the  pronator  teres,  sup- 
plying [this  muscle.  The  third  funiculus  immedi- 
ately divides;  one  branch  enters  a  sensory  path  in 
the  dorsal  part  of  the  nerve  trunk,  while  the  other 
has  been  followed  through  the  median  to  the 
forearm,  where  it  communicates  with  the  funicu- 
lus supplying  the  thenar  muscles.  Thus  it  will 
be  seen  that  in  these  types  of  communication  the 
musculocutaneous  nerve  may  supply  through  the 
median  the  humeral  head  of  the  pronator  teres,  the 
thenar  muscles  (abductor  pollicis,  opponens  pollicis 
and  flexor  pollicis  brevis) ,  as  well  as  some  sensory 
fibers  for  the  palm. 

It  is  difficult  to  believe  that  these  various  anoma- 
lies occur  merely  by  chance,  or  as  the  result  of  de- 
velopmental dift'erences  in  adjacent  structures. 
They  are  traceable  rather  as  variants  of  different 


Fig.  125. — Macerated  dissection  of  median  nen'e  (left) 
showing  communication  with  the  musculocutaneous  nerve. 
.4,  B,  C,  Communication  from  the  musculocutaneous  to  the 
median  nerve.  Bundle  A  joins  with  the  funiculus  i  for  the 
pronator  teres  and  flexor  carpi  radialis;  B  enters  the  dorsal  part 
of  the  trunk  to  pass  possibly  to  the  thenar  muscles;  C  rejoins 
the  musculocutaneous  nerve.  (Modified  after  Borchardt  and 
Wjasmenski.)' 


.lb 


VH 


RaJial  borA?r 


MUSCULOCUTANEOUS   NERVE  309 

degrees  from  some  primitive  pattern  in  the  development  of  the  two  nerves. 
Cruveilhier  (1851)  felt  that  the  origin  of  the  musculocutaneous  from  the 
outer  cord  explained  the  frequency  with  which  the  musculocutaneous  fused 
with  the  median  nerve.  While  this  may  be  true,  the  real  explanation 
goes  farther  back  in  the  phylogeny  of  these  two  nerves.  These  variations 
should  be  considered  as  regressive  phenomena  dating  to  the  time  when 
the  musculocutaneous  and  median  nerves  were  one  in  the  ruminants. 

Deformity. — In  complete  paralysis  of  the  musculocutaneous  nerve  the 
action  of  the  coracobrachialis,  biceps  and  brachialis  is  lost.  As  has  already 
been  said,  a  twig  from  the  musculospiral  supplies  the  latter  muscle  but  it  rarely 
gives  sufficient  innervation  to  permit  of  a  functional  contraction.  The  contour 
formed  by  the  biceps  is  absent  and  the  ventral  surface  of  the  arm  appears  more 
or  less  concave.  Flexion  of  the  forearm  is  not,  however,  completely  lost  due 
to  the  flexion  action  of  the  supinator  longus,  which  may  undergo  tremendous 
development  and  is  capable  of  forcible  flexion,  even  without  the  other  flexor 
muscles.  If  the  upper  extremity  be  allowed  to  hang  by  the  side  the  forearm 
cannot  be  flexed,  since  in  this  position  the  supinator  longus  is  unable  to  obtain 
the  necessary  leverage.  If  such  a  patient  is  examined  for  flexion  of  the  forearm, 
when  seated,  he  will  usually  swing  his  arm  so  that  Ms  hand  rests  upon  his  thigh 
and  thus,  with  the  forearm  slightly  bent,  he  will  be  able  to  continue  flexion 
with  considerable  force  solely  by  action  of  the  supinator  longus.  If  the  hand 
be  held  in  pronation,  occasionally,  the  supinator  longus  may  gain  sufficient 
leverage  during  efl^orts  at  supination  to  obtain  further  contraction  and  bring 
about  flexion. 

In  paralysis  of  the  biceps  and  brachialis,  if  the  forearm  be  held  in  semi- 
flexion the  supinator  longus  will  be  seen  as  a  strikingly  prominent  muscular 
band  forming  the  lateral  boundary  of  the  antecubital  fossa,  thus  by  its  promi- 
nence accentuating  the  absence  of  any  contour  formed  by  contraction  of  the  biceps. 

Rarely  the  pronator  teres  may  serve  as  a  flexor  in  combined  paralysis  of 
the  musculocutaneous  and  musculospiral  nerves  in  which  the  supinator  longus 
is  paralyzed  as  well  as  the  biceps  and  brachialis.  This  action  on  the  part  of 
the  pronator  teres  is  most  rare.  The  hand  is  held  in  full  pronation  and  flexion 
is  begun  by  passively  elevating  the  hand  a  short  distance  after  which  flexion  is 
completed  by  the  pronator  teres. 

The  shape  of  the  elbow-joint  mechanically  prevents  the  development  of 
deformity,  since  at  full  extension  the  olecranon  process  meets  bony  resistance 
against  the  olecranon  fossa. 


310       SURGICAL    AND    MECHANICAL  TREATMENT     OF  PERIPHERAL  NERVES 


Mechanical  Treatment. — Overstretching  of  the  biceps  is  unlikely,  due  to 
the  fact  that  other  muscles  of  different  nerve  supply  support  both  joints  over 
which  this  muscle  passes:  the  supinator  longus  flexing  the  elbow  and  the  triceps 
and  deltoid  supporting  the  humerus  at  the  shoulder.  However,  to  prevent 
adaptive  shortening  of  the  triceps  and  to  protect  the  muscles,  especially  from 
attempts  to  carry  heavy  weights  and  other  unguarded  movements,  the  forearm 
should  be  held  at  night  and  during  part  of  the  day  in  semiflexion,  the  hand  in 
supination  and  the  arm  drawn  toward  the  opposite  shoulder.     (See  Fig.  126.) 


A 


B 


Fig.  126. — Wrist  strap  for  paralysis  of  the  musculocutaneous.  A,  Arm  held  in  semiflexion 
and  drawn  across  to  the  opposite  shoulder.  Hand  is  held  in  supination.  Metal  dorsal  extension 
piece  supports  the  hand  and  prevents  it  from  falling  into  dependent  position.  The  small  strap  about 
the  wrist  is  attached  only  to  the  volar  surface  on  the  radial  side  and  passes  under  the  wrist,  thus 
assisting  in  maintaining  supination;  B,  to  illustrate  wrist  strap  and  metal  extension.  Leather 
covering  is  turned  back  showing  metal  piece  which  extends  from  wrist  across  dorsum  of  hand.  Note 
line  of  attachment  of  small  wrist  strap  and  that  it  passes  under  and  behind  the  wrist.  (Stookey, 
Surg.,  Gyn.  and  Obst.,  igi8.) 

For  this  purpose  a  simple  apparatus  similar  to  the  one  shown  should  be  worn. 

It  consists  of  a  broad  leather  cuff  fastened  to  a  collar  piece  by  a  pin  or  snap. 

The  wrist  band  includes  a  metal  plate  extending  forward  across  the  dorsum  of 

the  hand  and  wrist,  and  shaped  to  lit.     This  extension  serves  as  a  support  for  the 

hand    and    keeps    it    from    falling    down.     Without   such   an    extension  the 

patient  finds  a  wrist  strap  most  uncomfortable.     Supination  is  obtained  (see 

Fig.  1265)  by  means  of  a  small  support  strap  fastened  to  the  wrist  band  over  the 

volar  surface  of  the  radius  and  passed  outward,  and  under  the  wrist. 

Exposure  of  Musculocutaneous   Nerve  in    the  Axilla.     Position  of  the 

Arm. — A  sand  bag  is  placed  under  the  shoulder,  the  arm  is  held  horizontal 

and  at  right  angles  to  the  bodv. 


MUSCULOCUTANEOUS    NERVE  3II 

Incision,  15  cm.  long,  is  started  along  the  inner  margin  of  the  coracobrachi- 
alis  and  carried  upward  over  the  pectoralis  major  into  the  cleft  between  it  and  the 
deltoid.  The  cephalic  vein  should  be  saved  since  the  vein  within  the  axilla 
may  be  involved  in  scar  tissue.  After  the  skin  and  fascia  have  been  divided 
the  inner  margin  of  the  coracobrachialis  is  identified  and  thoroughly  exposed. 
The  pectoralis  major  overlies  the  field  anil  in  most  instances  must  be  cut  to 
obtain  a  thorough  exposure,  but  this  should  be  avoided  whenever  possible. 
If  the  muscle  be  cut  where  it  crosses  the  nerve,  resuture  will  be  difficult  since 
the  sutures  pull  in  the  direction  of  the  muscle  fibers,  and  hence  are  apt  to 
tear  out.  It  may  be  necessary  to  cut  only  the  lower  part  of  the  muscle  saving 
the  clavicular  head.  While  a  limb  already  weakened  by  paralysis  may  com- 
pensate for  loss  of  this  muscle,  it  is  undesirable  to  add  an  additional  motor  dis- 
ability if  it  can  be  avoided.  Instead  of  cutting  through  the  fleshy  part  of  the 
muscle,  the  insertion  of  the  pectoralis  major  may  better  be  exposed  and  a  disinser- 
tion  done.  (See  Fig.  120.)  At  the  line  of  insertion  the  periosteum  is  pushed 
back  and  a  small  bit  of  bone  together  with  the  insertion  is  chiselled  loose  and 
the  muscle  then  reflected.  After  the  operation  the  bone  is  replaced  and  the 
tendon  and  periosteum  sutured. 

The  nerve  may  be  identified  in  the  wound  by  following  the  medial  border 
of  the  coracobrachialis  muscle  to  the  point  at  which  the  nerve  enters  this  muscle. 
This  takes  place  very  near  to  the  origin  of  the  muscle,  approximately  3  cm. 
below  the  coracoid  process.  Numerous  nerves  and  blood  vessels  in  this  part 
may  confuse  the  field.  The  axillary  vein  lies  internal  to  the  artery  but  with 
the  arm  held  horizontal  to  the  body  the  vein  may  be  found  overlying  the 
latter.  Three  veins  may  be  encountered,  the  cephalic  and  the  two  venai 
comites  which  unite  at  the  lower  border  of  the  subscapularis  muscle  to  form  the 
axillary  vein.  Occasionally  the  union  is  effected  higher  so  that  four  veins  are 
seen,  the  fourth,  the  basilic  vein  which  usually  joins  the  inner  vena  comes 
below.  The  cephalic  vein  usually  enters  the  axillary  proximal  to  the  pec- 
toralis minor,  .\long  the  medial  border  of  the  musculocutaneous  nerve  and  in 
front  of  the  artery  lies  the  outer  head  of  the  median  nerve. 

Exposure  of  the  Secondary  Cords  of  the  Brachial  Plexus. — The  method 
just  given  for  exposure  of  the  musculocutaneous  nerve  within  the  axilla  may  also 
be  used  for  exposure  of  the  secondary  cords  of  the  brachial  plexus  and  is,  therefore, 
considered  here.  If  the  secondary  cords  of  the  brachial  plexus  are  to  be  repaired 
the  pectoralis  major  must  he  cut  or  disinserted  and  reflected  medially  to  e.xpose 
the  structures  of  the  axilla.     If  this  exposure  is  not  sufficient  then  the  pectoralis 


312       SURGICAL  AND  MECHANICAL    TREATMENT  OF    PERIPHERAL    NERVES 

minor  must  also  be  cut  and  reflected  in  a  similar  manner.  The  long  thoracic 
artery  should  be  isolated  before  cutting  this  muscle.  The  important  vessels  and 
nerves  should  be  freed  and  kept  in  view  to  avoid  injuring  them.  This  is  best 
accomplished  by  identifying  each  structure  distal  to  the  injury  and  dissecting 
upward  or,  when  necessary,  also  beginning  above  and  dissecting  downward. 
Injuries  in  the  axilla  usually  involve  at  least  two  nerves  in  combination;  on  the 
outer  side,  the  musculocutaneous  and  the  outer  head  of  the  median;  on  the 


Fig.  127. — Exposure  of  the  secondary  cords  of  the  Ijrachial  plexus  below  the  clavicle.  The 
inner  heads  of  the  median  and  the  ulnar  nerve  were  involved  in  scar  necessitating  excision  and 
suture.  The  pectoralis  major  has  been  disinserted,  the  pectoralis  minor  cut  and  both  have  been 
reflected  medially.  Running  over  the  insertion  of  the  pectoralis  minor  is  seen  the  cephalic  vein 
and,  immediately  beneath  the  muscle,  the  musculocutaneous  nerve  with  its  branch  to  the  coraco- 
brachialis  muscle. 


inner  side,   the  inner  head  of  the  median  and  ulnar  nerve,  or  the  ulnar  and 
musculospiral.     (See  Fig.  127.) 

The  axillary  vein  overlies  the  ulnar  nerve  and  the  inner  head  of  the  median- 
and  may  be  retracted  outward  by  cutting  one  or  two  of  its  branches  from  the 
anterior  thoracic  wall,  especially  the  dorsalis  scapulaj  and  the  long  thoracic. 
If  the  vein  is  also  imbedded  in  scar  tissue  liberation  may  not  be  possible  and 
section  of  the  vein  become  necessary.  This  can  be  done  safely  if  the  cephalic 
vein  uninjured  was  saved  when  the  skin  incision  was  made.  Lying  medial  and 
somewhat  dorsal   to   the  ulnar  the  musculospiral  nerve  will  be  found,  and 


MUSCULOCUTANEOUS    NERVE 


3'^3 


these  two  nerves  at  this  level  are  not  infrequently  injured  together.  The  mus- 
culospiral  nerve  may  be  seen  by  retracting  the  ulnar  nerve  and  the  axillary  vein 
inward;  the  nerve  is  then  sought  behind  the  axillary  artery.  If  this  does  not 
give  adequate  exposure  the  whole  neurovascular  bundle  may  be  rolled  outward 
after  cutting  a  few  of  the  smaller  vessels,  and  the  musculospiral  nerve  then  is 
brought  into  view  as  it  crosses  the  latissimus  dorsi  and  teres  major  tendons 


Bra^cKi-T^UsM.    Pectpr^UsMa^jor  M. 
C  Ot-8^cobra.«ni.a.lis  M. 


riu<:c.cat>.N.  / 

UU^rN. 


Outer  *  vnner 


Fig.  128. — Exposure  of  the  musculocutaneous  nerve  at  its  origin  with  cJirect  implantation  of 
the  nerve  into  the  biceps  muscle.  The  distal  end  of  the  nerve  was  too  extensiveh"  destroyed  to  permit 
suture.     Innervation  of  the  biceps  is  thus  gained  by  direct  implantation. 

(See  Fig.  log.)  As  the  nerve  lies  on  these  tendons  it  is  in  close  relation  to  the 
circumflex  nerve  which  is  given  off  the  dorsal  cord  just  before  it  reaches  the 
latissimus  dorsi  tendon. 

The  circumflex  nerve  passes  with  the  relatively  large  circumflex  artery  and 
vein  below  the  tendon  of  the  subscapularis  muscle.  If  the  musculospiral  fibers 
are  involved  central  to  the  circumflex  the  subscapular  nerves  may  be  endan- 
gered. The  short  subscapular  nerve,  often  double,  and  the  lower  subscapular 
pass  behind  the  circumflex  nerve,  on  the  ventral  surface  of  the  subscapular 
muscle,  supplying  this  muscle  and  the  teres  major.     The  long  subscapular 


314   SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERIPHERAL  NERVES 

is  distributed  to  the  latissimus  dorsi.  If  the  injury  is  too  near  the  main  nerve 
trunk  or  if  it  is  destroyed  at  the  origin  of  the  branches  and  suture  of  these 
is  not  possible,  the  central  ends  may  be  sutured  into  the  main  nerve  trunk,  or  if 
the  injury  is  more  distal  the  distal  ends  may  be  implanted  directly  into  the 
muscles  which  they  supply.     (See  Fig.  128.) 

In  operations  in  the  axilla  traumatic  aneurysm  either  arterial,  venous  or 
both  may  be  encountered  and  dealt  with.  If  ligation  is  necessary  the  liga- 
tures should  be  passed  both  centrally  and  distally  close  to  the  sac,  in  order  to 
save  as  much  of  the  artery  and  as  many  of  its  branches  as  possible  in  order  to 
permit  the  best  collateral  circulation. 

Exposure  of  the  Middle  Third  of  the  Musculocutaneous. — An  incision  is 
made  along  the  medial  border  of  the  biceps  and  after  the  latter  muscle  has  been 
retracted  outward  the  nerve  will  be  found  lying  beneath  the  biceps  and  upon 
the  brachialis.  In  this  region  the  motor  branches  to  the  biceps  and  brachialis 
are  given  ofT  and  careful  dissection  must  be  done  to  safeguard  them.  If  the 
nerve  is  injured  below  the  middle  third  only  sensory  branches  will  be  involved. 

Exposure  of  the  Cutaneous  Branch. — This  branch  is  desirable  for  use  in 
autogenous  nerve  grafts;  it  can  be  reached  through  the  same  incision  as  for  the 
lower  third  of  the  musculospiral.  If  the  outer  border  of  the  biceps  is  followed 
the  nerve  may  be  identified  as  it  emerges  from  beneath  this  muscle  to  pierce  the 
deep  fascia  a  little  above  the  biceps  tendon.  The  nerve  may  be  followed  higher 
up  by  retracting  the  biceps  inward  and  the  nerve  may  then  be  cut  at  the  junction 
of  the  middle  and  lower  thirds  of  the  humerus,  thus  obtaining  a  longer  nerve 
segment  for  graft  than  if  taken  only  at  the  point  where  it  emerges  from  beneath 
the  muscle,  as  is  usually  done.  By  dividing  the  nerve  in  this  lower  third  mus- 
cular branches  are  not  severed. 

Comment. — Following  suture  rapid  regeneration  of  the  musculocutaneous 
nerve  with  complete  return  of  function  in  its  muscles  may  be  e.xpected.  The 
muscular  portion  of  the  musculocutaneous  being  a  short  nerve  is  always  injured 
relatively  near  the  spinal  cord,  consequently  rapid  and  complete  regeneration 
usually  takes  place.  Also  its  muscles  are  not  directly  concerned  in  finer  move- 
ments and  hence  functional  return  is  apparently  more  complete.  Such  dis- 
abilities as  are  found  in  smaller  muscles,  concerned  with  movements  of  greater 
precision  and  dependent  upon  exact  proprioceptive  impulses,  are  not  felt  in  the 
large  flexor  muscles  of  the  arm  where  as  a  rule  movements  of  precision  and 
fineness  are  not  called  for. 


MUSCULOCUTANEOUS    NERVE  315 


REFERENCES 


CriA'eilhier,  J.:  Traite  D'anatomie  Descriptive,  4  vols.,  Labe,  ed.  3,  1851-52,  Paris. 
Gegenbaur,   C:    Ueber  das   Vcrhaltniss  des  N.  musculocutaneus  zum  N.  medianus,  Jen- 

aische  Zeitschrift  fiir  Medicin  und  Nalurwissenschafl,  v.  3:  1867,  p.  258. 
Gruber,  W.:  Xc-uc  .Xnomalicn  als  Beitrage  zur  physioiogischen  chirurgischen  und  patho- 

logischen  .\natomie,  Berlin,  \'erlag  von  .\lbert  Forstner,  1840. 
Cosset,  A.:  Resultats  fonctionnels  des  operations  faites  sur  les  nerfs  peripheriques.  Arch. 

de  med.  et  pharm.  mil.,  v.  60:   IQ18,  p.  304. 
Henle:  Ueber    Kriegsverletzungen    der    I'eripherischen    Xerven,    X'erhandl.    d.     deutsch. 

Gesellsch.  f.  Chir.,  v.  35:  pt.  2,  igo6,  p.  60. 
Herzog,  a.:  Zusammenstellung  von  150  Fallen  von  \'erletzungen  der  Nerven  der  oberen 

und  unteren  Extremitat,  Munch,  med.  Wchnschr.,  v.  64:   1917,  pp.  1021-1060. 
Hyrti. :  Ueber  das  Vorkommen  eines  dritten  Kopfes  des  Biceps  brachii,  Oesterreichische 

Zeitschrift  fiir  Praktische  Heilkunde,  185Q,  p.  47Q. 
Ingham,  S.  D.  and  Arnett,  J.  H.:  Diagnosis  of  peripheral  nerve  injuries  with  special  refer- 
ence to  compensatory  movements.  Arch.,  Neurol.  &  Psychiat.,  v.  3:   1020,  p.  107. 
Sherren",  J.:  Some  points  in  the  surgery  of  peripheral  nerves,  Edinburgh  M.  J.,  v.  62: 

igo6,  p.  207. 
Stopeord,  J.  S.   B.:  The   results  of  secondary   suture  of  peripheral   nerves.   Brain,  v.  43: 

pt.    I,     I<)20.    [).    I. 


CHAPTER  XIV 
MEDIAN  NERVE 

Anatomy. — The  median  nerve  is  formed  at  about  the  level  of  the  lower 
border  of  the  pectoralis  minor  muscle  by  junction  of  the  outer  and  inner 
heads,  arising  respectively  from  the  outer  and  inner  cords  of  the  brachial  plexus. 


Fro.  129. — Median  nerve.  Surface  projection,  i.  Median  nerve;  2  and  3,  branch  to  pronator 
teres;  4  and  5,  brancli  to  flexor  carpi  radialis,  palmaris  longus  and  flexor  digitorum  sublimis;  6, 
anterior  interosseous;  7,  brancli  to  flexor  pollicis  longus;  7',  branch  to  flexor  digitorum  profundus 
(index  and  middle  fingers);  8,  branch  to  pronator  quadratus;  q,  branch  to  abductor  pollicis  brevis, 
opponens  pollicis  and  flexor  pollicis  brevis  (superficial  head);  10,  cutaneous  digital  branches  and 
branch  to  lumbricales  (radial);  11,  communicating  branch  to  ulnar. 

Its  fibers  are  derived  from  the  ventral  divisions  of  the  brachial  ple.xus.  those 

of  the  outer  head  from  the  fifth,  sixth  and  seventh  cervical,  and  those  in  the 

inner  head  from  the  eighth  cervical  and  first  thoracic,  and  supply  muscles 

derived  from  the  primitive  ventral  musculature.     The  outer  head  lies  lateral 

to  the  axillary  artery,  and  the  inner  head  crosses  the  artery.     (See  Fig.  130.) 

Course. — In   the  arm   the  median   nerve  is  in   close  relation  with   the 

brachial  artery,  lying  to  its  outer  side  above,  and  to  its  inner  side  below,  cross- 

m6 


MEDIAN   NERVE 


317 


ing  in  front  the  artery  from  witliout  inward  at  about  the  middle  of  the  arm. 
At  the  ell)o\v  the  nerve  Hes  on  the  inner  side  of  the  artery  and  descends  into 
the  forearm,  passing  between  the  two  heads  of  the  pronator  teres,  separated 
at  this  point  from  the  uhiar  artery  by  the  ulnar  head  of  this  muscle.  The 
nerve  then  passes  between  the  deep  and  superficial  flexors  until  the  lower 
fourth  of  the  forearm  is  reached,  at  which  point  it  again  becomes  superficial, 
lying  immediately  beneath  the  tendon  of  the  palmaris  longus  muscle  and  radial 


fh  acr 


M. 


v 


1  -J/; 

V 

■  c 


Fig.  130. — Schematic  drawing  showing  variation  in  the  formation  of  the  median  nerve  and  abnormal 
position  of  the  artery.     (Ruge,  Morpholog.  Jahrbuch.) 


to  the  fie.xor  digitorum  sublimis.  The  nerve  is  superficially  placed  in  the 
arm  and  at  the  wrist,  but  lies  deeper  in  the  upper  three-fourths  of  the  forearm. 

The  nerve  enters  the  palm  of  the  hand  beneath  the  anterior  annular  liga- 
ment on  the  radial  side  of  the  flexor  tendons  of  the  fingers,  and  beneath  the 
palmar  fascia  it  breaks  up  into  its  terminal  branches.  In  the  forearm  it  is 
accompanied  by  a  small  vessel,  the  arteria  comes  nervi  mediani,  which  lies 
on  the  ventral  surface  of  the  median  nerve,  as  far  as  the  wrist. 

Variations  in  the  Formation  and  Course. — Numerous  variations  in  the 
formation  of  the  median  nerve  occur.  The  outer  and  inner  heads  may  be 
reduplicated  as  shown  in  Fig.  130,  a  third  head  of  origin  may  be  formed 
from  the  inner  cord  (Cruveilhier,  1851),  or  union  of  the  outer  and  inner  heads 
may  take  place  in  the  middle  of  the  arm,  or  as  far  down  as  the  elbow.  The  rela- 
tion of  the  median  nerve  to  the  brachial  arterv  mav  varv-     The  outer  head  of 


3l8       SURGICAL    AND    MECHANICAL  TREATMENT  OF    PERIPHERAL    NERVES 

the  median  may  pass  behind  the  artery  to  join  the  inner  head,  while  in  the  arm 
the  nerve  may  pass  behind  the  brachial  artery,  remain  parallel  to  the  artery, 
or  pass  either  medial  or  lateral  to  it.     Gruber  (1867)  found  in  one  hundred 


Sr- 


A  B 

Fig.  131. — Schematic  drawing  to  show  variation  in  the  relation  of  the  median  nerve  to  the 
axillary  and  brachial  artery.  .1,  Outer  head  of  the  median  is  seen  passing  beneath  artery;  B,  high 
division  of  brachial  artery  with  median  nerve  lying  between  the  two  branches.  (Ruge,  ilorpholog. 
Jahrbuch.) 


cadavers  that  the  nerve  passed  beneath  the  artery  in  20%,  remained 
parallel  to  it  in  89c.  passed  lateral  in  3'Je  and  internal  in  8%,  the  remainder 
following  the  usual  course.  Some  variations  are  more  anomalies  in  the  course 
of  the  brachial  artery  than  anomalies  in  the  formation  of  the  median  nerve. 


MEDIAN   NERVE  319 

Occasionally  the  brachial  artery  may  be  divided  high  in  the  arm  and  the  median 
nerve  found  between  the  two  branches.  (See  Fig.  131.)  In  its  course  the 
nerve  may  not  enter  its  deep  position  in  the  forearm  by  passing  between  the 
two  heads  of  the  pronator  teres,  but  may  lie  superficial  to  this  muscle.  In  rare 
instances  a  bony  process  may  be  found  along  the  medial  supracondylar  ridge 
known  as  the  epicondylic  process  behind  which  the  median  nerve  and  brachial 
artery  may  pass,  or  if  the  process  forms  a  bony  or  fibrous  canal,  as  reported  by 
Gruber  (1867),  Ruge  (1884),  these  structures  may  be  inclosed  within  it.  Such  a 
canal  may  be  considered  as  atavistic,  it  being  regularly  present  in  some  of  the 
climbing  mammals. 

Branches.  In  the  Arm. — There  are  no  motor  branches  in  the  arm  except- 
ing in  the  lower  part  of  the  lower  third,  at  which  level  one  or  two  nerves  may 
be  given  off  for  the  humeral  head  of  the  pronator  teres.  However,  infrequently, 
two  branches  arise  in  the  middle  third  of  the  arm,  one  a  small  articular  branch 
which  leaves  the  dorsal  radial  part  of  the  nerve  trunk  and  courses  beside  the 
brachial  artery  to  the  elbow- joint,  where  it  divides,  and  then  turns  deeply  to 
supply  the  elbow-joint.  According  to  Frohse  and  Frankel  (1908),  this  nerve 
ends  occasionally  in  the  brachialis  and  has  been  called  by  them  the  ramus 
collateralis  nervi  mediani.  In  about  one-third  of  the  cases  a  relatively  promi- 
nent communication  is  given  off  from  the  musculocutaneous  to  the  median. 
(See  Fig.  132.)  This  communication  consists  generally  of  both  sensory  and 
motor  fibers  which  may  pass  from  the  median  to  the  musculocutaneous  or 
from  the  musculocutaneous  to  the  median. 

Motor  Bra  utiles  in  the  Lou'er  Part  of  the  Arm. — The  first  motor  branches 
are  those  to  the  pronator  teres,  humeral  head,  generally  two  in  number,  one 
to  the  upper  and  the  second  to  the  lower  part  of  this  portion  of  the  pronator 
muscle.  These  branches  generally  leave  the  nerve  trunk  on  the  ulnar  border, 
though  they  may  cross  over  from  the  radial  side,  in  front  of  the  nerve  trunk 
and  enter  the  muscle  almost  immediately  below  their  origin,  having  a  com- 
paratively short  c.xtramuscular  course.     (See  Fig.  132.) 

Branches  in  the  Forearm. — (i)  The  next  branches  are  those  to  the  pronator 
teres  (ulnar  head)  and  also  occasionally  a  small  branch  to  the  inferior  part  of 
the  humeral  head.  These  branches  arise  from  the  radial  and  ventral  side  in 
the  region  of  the  elbow-joint,  just  as  the  median  nerve  passes  between  the  two 
heads  of  the  pronator  ter^.      (See  Fig.  133.) 

Branches  for  the  flexor  carpi  radialis  arise  in  the  region  of  the  elbow, 
generally  from  the  ulnar  border,  though  they  may  arise  from  the  radial  side,  in 


320        SURGICAL    AXD     MECHAXICAL     TREATMENT     OF    PERIPHERAL  NERVES 


Median  NlefH 


Musculocu-tancous  N. 


ConiTnunicaiion 
tofuuiciilusof 

px-ooaiorfsna- 
6  fUx  cd^rpi 


Elbow 


U 


MuscniocuiAnsouS  N. 
cuta-tuous  br. 


Ultiir  boT<3cr 


5  -. 


-lb 


■;.-H 


Raxlid^l  tor<ier 


which  case  they  pass  over  immediately  to  the  ulnar 
side,  enter  the  flexor  carpi  radialis  muscle  and  break, 
up  into  numerous  small  twigs. 

The  muscular  branches  to  the  pronator  teres 
and  the  flexor  carpi  radialis  (la,  ib.  ic)  constitute 
a  single  funiculus  (see  Fig.  134)  which  may  be 
traced  centrally  as  far  as  the  union  of  the  outer 
and  inner  heads  of  the  median  nerve.  According 
to  Borchardt  (1917),  the  position  of  this  funiculus 
within  the  nerve  trunk  varies  greatly.  In  the  up- 
per part  of  the  arm  it  lies  upon  the  ventral  and 
medial  portion  of  the  nerve  trunk,  gradually  turn- 
ing toward  the  xentral  and  radial  border,  in  which 
position  it  has  been  found  by  Marie,  Gosset  and 
Meige  (1915).  However,  in  bipolar  electrical  stim- 
ulation tests,  instead  of  crossing,  it  may  be  found 
to  descend  upon  the  ulnar  side  of  the  nerve.  Elec- 
trical stimulation  of  the  outer  and  inner  heads  of 
the  median  nerve  tends  to  show  that  the  fibers 
destined  for  the  pronator  teres  lie  in  the  inner 
head  of  the  median  nerve,  and  those  for  the  flexor 
carpi  radialis  in  the  outer  head. 

Fig.  132. — Macerated  dissection  of  median  nerve  (left) 
showing  communication  with  the  musculocutaneous  nerve. 
A,  B,  C,  Communication  from  the  musculocutaneous  to  the 
median  nerve.  Bundle  --1  joins  with  the  funiculus  i  for  the 
pronator  teres  and  flexor  carpi  radialis;  B  enters  the  dorsal  part 
of  the  trunk  to  pass  possibly  to  the  thenar  muscles;  C  rejoins 
the  musculocutaneous  nerve,  i,  la,  16.  ic  is  the  common  path 
for  the  pronator  teres  and  flexor  carpi  radialis.  Note  that  this 
bundle  crosses  the  nerve  diagonally  a  little  below  the  level  of 
the  elbow;  2,  2a,  2b  is  the  funiculus  for  the  fle.xor  indicis  sub- 
Hmis  (sup.  belly)  and  palmaris  longus,  20  for  the  flexor  indicis 
sublimis  and  26  for  the  palmaris  longus.  In  this  position  this 
path  Hes  on  the  ulnar  border;  3  is  the  bundle  to  the  fle.xor 
digitorum  subhmis  of  the  3d,  4th,  and  3th  fingers;  4  is  the  bundle 
to  the  flexor  digitorum  profundus,  flexor  poUicis  longus  and 
the  anterior  interosseous  nerve.  This  path  crosses  below  the 
level  of  the  elbow  dorsally  from  the  ulnar  to  the  radial  border; 
3,  bundle  to  the  deep  belly  of  the  flexor  indicis  sublimis.  From 
this  dissection  it  will  be  noted  that  identification  of  any  one 
bundle  can  be  made  only  over  a  comparatively  short  course 
and  that  fusion  and  intermingling  of  bundles  is  frequent. 
(Modified  after  Borchardt  and  Wjasmenski.) 


MEDIAN   NERVE 


321 


R    superior  (pro  ventre  supenon  di 


Corpusculum  lamello^um  (Vatkh 


R.  medius  (pro  digitis 
III,  IV  et  V) 


R.  inferior  (pro  ventre 
inferiori  digiti  II) 


Fig.   133. — Nerve  distribution  in  the  flexor  digitorum  sublirais.     (Frohse  and  Frankel.) 


322       SURGICAL    AND     MECHANICAL     TREATMENT    OF    PERIPHERAL    NERVES 

Median   N,  rijhi 


Outer  head 


Inner  head 


Radial  border     \M        ;W///  Ulnir  border 


Musculo- 
cutaiicousN   -.._ 
(muscular  brs } 


A  -i 


Cutaneous      //// 
braticKes 


Elbow  , 


Ulbk 


Ulblc 


l&lblc 


u 


Fig.  134a. — Median  and  musculocutaneous  nerves,  macerated  dissection.  Bundle  i,  la,  ib, 
ic  lies  on  the  ulnar  border  below  and  crosses  to  the  radial  above.  The  bundle  to  the  pronator  teres, 
13  and  16,  passes  through  the  inner  head  of  the  median  and  the  bundle  to  the  flexor  carpi  radialis,  if, 
through  the  outer  head.  On  the  ulnar  side  of  the  bundle,  i,  la,  ib,  ic,  lies  the  bundle  for  thefle.xor 
indicis  sublimis  (sup.  head).  This  bundle  and  the  bundle  to  the  flexor  digitorum  sublimis,  3d,  4th, 
5th  fingers,  3,  pass  through  the  inner  head.  The  cross  section  appearances  of  v-arious  levels  at  2-cm. 
intervals  are  shown.  Note  the  marked  difference  of  the  cross  section  appearance  at  each  level. 
(Modified  after  Borchardt  and  Wjasmenski.) 


MEDIAN    NERVE 


323 


Median   N,  left. 
Ulnar boriai-  illl        Ra-Jua.!  border 


1— - 


Arlicalat  br. 


^      iivfelb 


-  Elbow 


Fig.  134^. — Left  median  nerve,  macerated  dissection.  The  typical  course  of  the  bundle  to  the 
pronator  teres  and  fle.xor  carpi  radialis  is  shown,  i,  la,  li,  ic,  passing  from  the  radial  border  in  the 
middle  of  the  arm  to  the  ulnar  border  below.  Cross  sections  are  shown  at  2-cm.  intervals;  each 
section  is  placed  at  its  corresponding  level.  Note  the  marked  variation  in  the  cross  section  appear- 
ance of  each  succeeding  level.     (Modified  after  Borchardt  and  Wjasmenski.J 


324      SURGICAL    AND    MECHANICAL  TREATMENT    OF    PERIPHERAL     NERVES 

Immediately  below  the  origin  of  the  preceding  branches,  a  branch  arises 
for  the  flexor  indicis  sublimis  (superior  belly)  {2a  and  2b)  which  divides  to  supply 
this  muscle  and  the  palmaris  longus.  This  branch  arises  from  the  ulnar  border 
of  the  nerve  trunk,  where  the  median  nerve  lies  between  the  two  heads  of  the 
pronator  teres.  The  funiculus  for  this  lies  on  the  ulnar  or  medial  border  of  the 
inner  head  of  the  median  and  then  descends  upon  the  ulnar  on  the  dorsal  part  of 
the  nerve  trunk.  It  lies  in  close  proximity  with  the  funiculus  for  the  deep 
flexors,  (see  Fig.  132)  with  which  it  communicates  at  numerous  points.  It 
then  gradually  turns  more  ventrally,  though  still  upon  the  ulnar  border,  and  is 
placed  ventral  to  the  most  medial  funiculus  of  the  trunk,  close  to  the  funiculus 
for  the  flexor  carpi  radialis  (ic),  at  the  point  where  the  latter  crosses  the 
nerve. 

The  next  branch  given  off  is  to  the  flexor  digitorum  sublimis  of  the  third, 
fourth  and  fifth  fingers  (3) ,  which  arises  from  the  ulnar  and  ventral  side  of  the 
nerve  trunk,  5  to  6  cm.  below  the  medial  condyle  and  2  or  3  cm.  below 
the  branch  to  the  flexor  carpi  radialis  (ic).  This  funiculus  is  found  as 
a  distinct  path  only  a  few  centimeters  above  the  medial  condyle,  where  it 
fuses  with  a  funiculus  along  the  ulnar  side  of  the  median  nerve  consisting 
mostly  of  afferent  fibers. 

At  about  the  same  level  as  the  above  branch  the  branch  for  the  deep 
flexors  (4)  arises  from  the  ulnar  side  of  the  dorsal  surface  of  the  nerve  trunk  at 
the  upper  margin  of  the  pronator  teres.  It  first  descends  along  the  ulnar 
border,  thence  crosses  behind  the  nerve  trunk  to  the  lower  border  of  the  ulnar 
head  of  the  pronator  teres.  It  supplies  twigs  to  the  flexor  digitorum  profundus 
for  the  second  and  third  fingers  and  the  flexor  pollicis  longus  muscles,  and  termi- 
nates as  the  anterior  interosseous  nerve,  which  also  gives  oft"  twigs  at  a  lower 
level  to  the  same  muscles.  The  anterior  interosseous  nerve  descends  in  front 
of  the  interosseous  membrane,  covered  by  the  radial  border  of  the  flexor 
digitorum  profundus  muscle,  and  ends  upon  the  deep  surface  of  the  pronator 
quadratus,  which  it  supplies  together  with  the  wrist-joint.  A  small  branch  is 
given  off  in  the  middle  of  the  forearm  from  the  dorsal  ulnar  part  of  the  nerve 
trunk  to  the  lower  belly  of  .the  flexor  indicis  sublimis. 

The  dual  supply  of  the  flexor  pollicis  longus,  flexor  digitorum  profundus 
(2  and  3)  and  the  flexor  indicis  sublimis  (see  Fig.  133)  may  be  of  great  practical 
service  in  those  cases  in  which  the  median  nerve  is  injured  at  the  level  of  the 
elbow,  with  destruction  of  the  upper  set  of  muscular  branches  at  this  point.  For 
if  the  nerve  can  be  brought  together  and  regeneration  occur,  function  may  be 


MEDIAN    NERVE  325 

re-established  in  the  above-mentioned  muscles  by  means  of  the  lower  set  of 
branches  in  spite  of  the  loss  of  the  others. 

Branches  at  the  Wrist. — Several  centimeters  above  the  anterior  annular  liga- 
ment a  palmar  cutaneous  branch  arises,  which  supplies  the  skin  of  the  palm  of  the 
hand.  Approximately  2  to  3  cm.  below  the  anterior  annular  ligament  the  mus- 
cular branch  for  the  thenar  muscles  (abductor  pollicis,  opponens  pollicis,  and 
lle.xor  pollicis  brevis)  arises  from  the  radial  and  dorsal  surface.  Within  the  palm 
the  median  nerve  then  breaks  up  into  its  terminal  branches,  five  in  number, 
which  pass  between  the  palmar  arch  and  the  flexor  tendons,  to  supply  both  the 
radial  and  the  ulnar  side  of  the  thumb,  the  radial  side  of  the  index  finger,  the 
first  lumbrical  muscle,  the  adjacent  sides  of  the  index  and  middle  fingers, 
the  second  lumbrical  muscle  and  the  adjacent  sides  of  the  middle  and  ring  fingers. 

Anomalies. — Variation  in  distribution  of  the  median  and  ulnar  nerves 
takes  place  often  in  the  forearm,  in  the  hand,  and  at  times  in  the  arm  or  axilla. 
These  communications  have  been  described  by  many  of  the  older  anatomists. 
Gruber  (1870)  found  a  communication  between  the  median  and  ulnar  nerves 
thirty-eight  times  in  a  hundred  and  twenty-five  cadavers  examined.  In  ten 
subjects  the  communication  was  bilateral  and  in  the  remainder  it  occured  four- 
teen times  on  the  left  side,  four  times  on  the  right.  Thompson's  (1891)  report  on 
four  hundred  and  six  cadavers  found  such  a  communication  to  be  present  in 
15%-     Four  types  of  communication  were  described: 

(a)  A  communication  arose  from  the  anterior  interosseous  nerve  about 
5  cm.  below  its  origin  and  joined  the  ulnar  nerve  in  its  middle  third,  passing 
below  the  ulnar  artery  upon  the  flexor  digitorum  profundus. 

{b)  A  communication  arose  from  the  main  nerve  trunk  of  the  median 
and  joined  the  ulnar  in  the  same  manner  as  in  (a). 

(c)  A  sling  communication  occurred  over  the  flexor  digitorum  profundus 
formed  by  both  median  and  ulnar  nerves  with  branches  from  the  sling  supplying 
the  flexor  digitorum  profundus  to  the  third  and  fourth  fingers. 

{d)  A  branch  from  the  median  nerve  arose  in  the  region  of  the  elbow, 
passed  superficial  to  the  flexor  muscles  arising  from  the  medial  condyle,  and 
joined  the  ulnar  nerve  in  its  middle  third. 

In  tracing  some  of  these  communications  Borchardt  (191 7)  found  that  the 
communication  to  the  ulnar  nerve  divided  into  two  portions,  one  joining  a 
sensory  pathway  and  the  other  a  motor.  The  fibers  of  the  sensory  path  joined 
that  part  of  the  ulnar  nerve  which  supplies  the  skin  on  the  inner  part  of  the 
palm,  the  palmaris  brevis  muscle  and  the  fourth  and  fifth  fingers,  while  the 


326       SURGICAL  AND  MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

muscular  branch  joined  that  part  of  the  ulnar  nerve  which  supplies  the  intrin- 
sic muscles  of  the  hand.     (See  Fig.  151.) 

In  the  hand  there  are  two  communications  between  the  median  and  ulnar 
nerves  of  rather  minor  importance.  One  twig  is  sensory,  for  the  adjacent  sur- 
faces of  the  third  and  fourth  fingers,  while  the  other  is  motor,  between  the  deep 
branch  of  the  ulnar  and  the  motor  branch  of  the  median  nerve  to  the  thenar 
muscles.     According  to  Frohse  (1908)  this  branch  is  constantly  present,  passing 


Tendon 
sheath  ■ 


Tendon  of  M. 
flexor  polUcis 
longus 


Ulnar    and   radial 
sesamoid  bones 


f  caput 
j  superfi- 

M.  flexor  pollicis  I  ciale 

brevis 


aput  profundiim 


uscularis  n.  median 


Articulatio   carpo-metacarpea  pollicis- 

Os  multangulum  majus 


Lig.     carpi     transversum     cut    and    reflected 


Os 
capitatum 


Tendon  M.  abductor  pollicis  longus 
Fig.  135. — Nerve  distribution  to  the  thenar  muscles,  deep  surface.     (Frohse  and  Friinkel.) 


through  the  abductor  pollicis  muscle  and  along  the  flexor  pollicis  brevis.  (See 
Fig.  135.)  This  branch  is  difficult  to  follow  except  in  specially  prepared  speci- 
mens though  clinical  evidence  of  this  communication  has  been  observed  in  cases 
in  which  severance  of  the  median  nerve  above  the  wrist  occurred  without  any 
paralysis  of  the  muscles  of  the  thenar  eminence.  The  abductor  pollicis  brevis 
frequently  receives  a  twig  from  the  radial  nerve  which  is  considered  motor  by 
some,  while  others,  notably  Frohse  and  Frankel,  believe  that  this  twig  does  not 
end  in  motor  end  plates  but  in  sensory  nerve  endings. 

Anomalies  in  distribution  of   the  median  and  ulnar  nerves  have  been 


MEDIAN    NERVE  327 

encountered  clinically  as  well  as  anatomically.  Goklmann  (1906)  Auerbach 
and  Brodnitz  (1910),  Halipre  (1917)  and  others  have  reported  cases  in  which, 
in  spite  of  severance  of  the  ulnar  nerve,  no  paralysis  in  the  muscles  of  the  hand 
occurred.  In  these  instances  the  innervation  of  all  the  intrinsic  muscles 
of  the  hand  has  been  attributed  to  the  median  nerve.  Evidence  of  such  a  dis- 
tribution of  the  median  nerve  I  have  seen  in  one  of  my  own  cases.  The  diag- 
nosis of  an  ulnar  nerve  tumor  was  made  because  of  the  presence  of  a  tumor  in 
the  middle  third  of  the  arm  apparently  arising  from  the  ulnar  ner\-e  with 
subjective  tingling  and  numbness  referred  to  the  fourth  and  tifth  finger  and 
also  a  sensation  as  if  a  knife  were  drawn  down  the  middle  of  the  fourth 
finger  when  the  tumor  was  pressed  upon.  At  operation  a  tumor  of  the 
median  nerve  in  the  middle  third  of  the  arm  was  found.  To  make  certain 
that  no  error  in  identification  of  the  ner\es  had  been  made  the  ulnar  nerve 
was  exposed  in  the  groove  behind  the  medial  condyle.  The  nerve  was  traced 
upward  a  short  distance  sufficient  to  demonstrate  that  the  ulnar  nerve  did 
not  join  the  median  below  the  tumor.  At  the  time  of  operation  it  was  thought 
that  a  mistake  in  diagnosis  had  been  made  and  that  the  ulnar  signs  present 
were  due  to  pressure  of  the  tumor  secondarily  upon  the  ulnar  nerve.  The 
median  nerve  was  then  fully  e.xposed  and  its  course  toward  the  front  of  the 
elbow  determined.  Excision  of  the  tumor  with  end-to-end  suture  was  done. 
Following  the  operation  complete  paralysis  of  the  median  and  ulnar  muscles  of 
the  hand  and  forearm  was  found  as  well  as  complete  median  and  ulnar  anesthesia. 

In  Goldmann's  case,  a  tumor  and  5  cm.  of  the  ulnar  nerve  was  removed 
above  the  elbow  with  no  disturbance  in  the  motility  of  the  hand  and  fingers. 
Auerljach  and  Brodnitz  likewise  found  no  motor  paralysis  in  the  ulnar  distri- 
bution, after  complete  section  of  the  ulnar  nerve  above  the  elbow  with  excision 
of  a  nerve  tumor.  Halipre  also  found  that  in  complete  severance  of  the  ulnar 
nerve  above  the  elbow  there  was  no  motor  loss  in  the  ulnar  distribution  and  that 
at  operation  stimulation  of  either  end  of  the  ulnar  nerve  gave  no  response,  but 
when  the  ulnar  nerve  was  stimulated  lower  down  contraction  in  the  ulnar 
distribution  followed.  The  cases  of  Goklmann,  Auerbach  and  Brodnitz  indi- 
cate in  a  negative  manner,  as  it  were,  that  the  median  nerve  may  take  over 
the  supply  of  the  ulnar,  while  my  own  case  showed  that  this  supply  is  in  fact 
taken  over  by  the  median,  since  severance  of  the  median  nerve  resulted  in  not 
only  median  but  in  ulnar  paralysis  as  well. 

From  a  developmental  standpoint  association  in  the  distribution  of  the 
median  and  ulnar  nerves  is  seen  in  the  common  supply  by  these  nerves  of  the 


328   SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERIPHERAL  NERVES 

same  muscle  mass  with  overlapping,  for  loss  of  one  nerve  may  result  in  only 
partial  paralysis.  (See  Fig.  136.)  Thus  the  intact  nerve  by  its  partial  supply 
may  mask  the  motor  loss,  assuming,  in  a  measure,  the  function  of  the  other. 
This  is  seen  in  the  nerve  supply  to  the  flexor  digitorum  profundus  of  the  third 
finger,  in  which  there  is  some  overlapping  of  both  the  ulnar  and  median  innerva- 
tion. In  some  instances,  the  median  nerve  may  extend  its  fibers  to  the  flexor  of 
the  fourth  and  fifth  fingers,  but  the  ulnar  nerve  never  extends  beyond  the  flexor 
of  the  third  digit.  The  flexor  of  the  index  finger,  is  supplied  only  by  the 
median  nerve.  Consequently,  following  median  nerve  injuries,  the  oifly  ap- 
parent paralysis  which  may  be  observed  in  the  flexors  of  the  fingers  is  that  of 
flexion  of  the  index  finger  and  thumb,  while  in  ulnar  paralysis  flexion  may  be 
carried  on  in  all  fingers  through  median  nerve  action. 

Deformity. — Complete  injury  of  the  median  nerve  above  the  elbow  involves 
the  flexors  of  the  wrist,  fingers  and  thumb,  the  pronator  teres  and  pronator 
quadratus  as  well  as  the  opponens  pollicis,  flexor  poUicis  brevis  and  superficial 
head  of  the  abductor  pollicis.  Of  the  flexor  muscles  of  the  forearm  the  flexor 
carpi   ulnaris  and  ulnar  portion  of  the  flexor  digitorum  profundus  escape. 

Loss  of  contour  on  the  ventral  surface  of  the  forearm  is  seen  and  a  small 
transverse  furrow  can  be  felt  over  the  metacarpal  bone  of  the  thumb.  This 
latter  depression  is  characteristic  and  constant  in  atrophy  of  the  opponens 
muscle.  Flexion  of  the  wrist  is  accomplished  by  the  flexor  carpi  ulnaris  wliich 
usually  draws  the  wrist  toward  the  ulnar  side  due  to  the  absence  of  the  pull  of 
the  flexor  carpi  radialis.  The  flexor  carpi  ulnaris  may  produce  forcible  flexion 
of  the  wrist  and  this  muscle  can  be  developed  in  re-education  when  in  median 
injuries  flexion  has  been  lost.  Pronation  may  be  done  by  the  supinator  longus 
if  its  insertion  is  placed  slightly  on  the  dorsal  surface  of  the  radius,  as  is  often 
the  case.  Flexion  of  the  third,  fourth  and  fifth  fingers  is  accomplished  through 
the  ulnar  nerve,  though  flexion  at  the  proximal  interphalangeal  joints  alone 
cannot  be  done.  The  thumb  and  index  finger  cannot  be  flexed  for  their  muscles 
are  supplied  exclusively  through  the  median,  with  the  exception  of  the  deep  head 
of  the  flexor  pollicis  brevis,  and  consequently  their  action  cannot  be  accomplished 
through  ulnar  nerve  action. 

In  high  injuries  involving  only  part  of  the  median  nerve  inability  to  flex 
the  index  finger  may  be  the  only  striking  motor  sign  of  such  injury.  This  fact 
has  been  used  by  exponents  of  funicular  anatomy,  particularly  Stofl'el  (19 13),  as 
distinct  evidence  of  the  presence  of  a  separate  and  distinct  funiculus,  existing 
as  such,  from  the  origin  of  the  median  nerve  to  the  branches  supplying  this 


MEDIAN    NERVE 
N.?nedian 


3^9 


M.  Jlex.  carp,  utn. 


ir  111 

M.  flex,  digit,  prof. 


it.  flex.  poll.  lung. 


Fig.  136. — Nerve  distribution  to  the  flexor  carpi  ulnaris,  flexor  digitorum  profundus  and  abductor  or 
flexor  pollicis  longus.     (Frohse  and  Frankel.) 


330       SURGICAL    AND     MECHANICAL    TREATMENT     OF     PERIPHERAL     NERVES 

muscle.  If  such  an  explanation  were  correct  it  would  seem  curious  that  almost 
constantly  such  an  injury  should  select  this  particular  funiculus  without  impli- 
cating the  others.  Such  an  apparent  dissociated  lesion,  relatively  common 
in  the  median  nerve,  is  rather  infrequent  in  other  nerves.  The  real  explanation 
may  be  found  not  in  the  funicular  arrangement  and  the  fact  that  this  funiculus 
does  have  a  very  long  and  separate  course,  but  more  likely  in  the  fact  that  the 
flexor  indicis  sublimis  is  exclusively  supphed  by  the  median  nerve  so  that 
supplementary  innervation  does  not  take  place  as  occurs  in  other  muscles 
supplied  conjointly  by  ulnar  and  median  nerves.  Not  only  are  the  flexors  of 
the  index  paralyzed,  but  also  the  other  median  flexors.  The  paralysis  of  the 
latter  with  the  exception  of  the  flexors  of  the  thumb  and  index  is  masked  by  the 
action  of  the  ulnar  flexors,  while  the  action  of  the  flexors  of  the  index  is  not  com- 
pensated for  and  hence  inability  to  flex  the  index  may  be  the  only  striking  sign. 

Perhaps  one  of  the  most  characteristic  paralyses  in  the  hand  following 
median  nerve  injury  is  loss  of  the  opponens  action  of  the  thumb.  This  move- 
ment maybe  closely  similated  by  rotation  and  flexion  of  the  thumb,  the  thumb 
skirting  the  base  of  the  metacarpophalangeal  joints  by  action  of  the  abductor 
pollicis  and  the  flexor  pollicis  brevis.  True  median  opponens  action  can  be 
said  to  be  accomplished  only  when  the  palmar  surface  of  the  distal  phalynx 
of  the  thumb  is  in  apposition  with  that  of  the  fifth  finger,  the  interphalangeal 
joints  of  both  being  fully  extended. 

Mechanical  Treatment. — In  median  nerve  paralysis  overstretching  of  the 
flexor  muscles  is  not  apt  to  occur,  for  integrity  of  the  flexors  supplied  by  the 
ulnar  nerve  prevents  contractures  by  maintaining  the  mobility  in  the  muscles 
and  joints.  Flexion  and  extension  of  the  fingers  through  ulnar  nerve  action 
passively  move  the  median  flexor  tendons,  thus  improving  the  circulation  and 
nutrition  of  the  paralyzed  muscles  and  preventing  adhesions  in  their  tendon 
sheaths.  However,  the  thumb  and  index  finger  do  not  participate  in  these 
movements  and  mobility  must  be  secured  by  passive  movements.  Patients 
with  median  nerve  injuries  formerly  were  given  a  straight  finger  splint  for  each 
finger,  but  further  experience  taught  that  splinting  in  these  cases  is  not  of  any 
material  help  since  overstretching  does  not  occur.  If  stiffness  develops  in  the 
thumb  and  index  finger  they  may  be  splinted  alternately  in  flexion  and  exten- 
sion. For  example,  a  flexion  splint  may  be  worn  during  the  day  and  the  splint 
reversed  during  the  night.  (See  Figs.  137,  138  and  139.)  The  Zander  finger 
machines  are  particularly  useful  to  help  maintain  the  normal  mobility  in  these 
two  fingers. 


MEDIAN    NERVE  33 1 

In  median  nerve  neuritis  contractures  may  be  severe  and  tax  the  ingenuity 
of  the  surgeon  to  devise  spHnts  wliicli  will  <)\-ercome  the  contractures  and  yet  not 


Fig.  137. — Splint  for  median  paralysis  applied.     Finger  pieces  are  made  of  thin  board  held  to- 
gether by  strips  of  adhesive  tape.     (Buerki,  .Archives  of  Neurology  and  Psychiatry,  iq2o.) 


Fic.  138. — First  position  of  twelve-hour  splints  for  cases  of  fixation  of  the  fingers.  The  splint 
is  worn  in  this  position  for  twelve  hours  out  of  the  twenty-four.  (Buerki,  .Archives  of  Neurology 
and  Psychiatry,  1920.) 

produce    contractures    in    ovcrcorrected    positions.     Immobilization    in    over- 
corrected  positions  cannot  alone  suffice,  for  contractures  at  once  occur  in  the 


332       SURGICAL    AND     MECHANICAL      TREATMENT    OF  PERIPHERAL    NERVES 

new  and  equally  vicious  position.     In  these  cases  particularly,  mobilization 
must  be  combined  with  immobilization  and  each  case  dealt  with  individually. 

Exposure  of  the  Median  Nerve.  Position  of  the  Arm. — The  arm  is  held 
at  right  angles  to  the  body  with  the  forearm  slightly  flexed  to  relax  the 
nerve.  When  the  arm  is  fully  extended  the  nerve  is  stretched  and  may  be 
concealed  beneath  the  border  of  the  biceps  muscle.  In  operations  in  the 
forearm  the  wrist  should  also  be  flexed. 


Fig.  139. — Second  position  of  twelve-hour  splints.     (Buerki,  Archives  of  Neurology  and 

Psychiatry,  1920.) 

Incision. — Exposure  of  the  median  nerve,  except  the  part  beneath  the 
humeral  head  of  the  pronator  teres,  offers  no  difficulty.  By  retracting  the 
pectoralis  major  muscle  upward  and  inward  the  nerve  may  be  exposed  along  the 
inner  surface  of  the  arm  as  far  up  as  the  union  of  the  outer  and  inner  heads. 
(See  Figs.  140,  141,  142  and  143.)  An  incision  along  the  medial  border  of  the 
biceps  will  readily  bring  the  nerve  in  the  arm  into  view.  In  muscular  subjects 
with  well-developed  biceps  the  nerve  will  be  found  hidden  beneath  the  border 
of  this  muscle.  Its  relation  to  the  brachial  artery  has  already  been  mentioned- 
The  funiculus  to  the  pronator  teres  is  importnat  since  it  has  a  more  or  less  con- 
stant position  in  the  nerve  trunk  near  the  place  at  which  the  upper  motor 
branches  are  given  off,  viz.,  the  lower  one- third  of  the  arm  and  the  upper 
one-third  of  the  forearm.  Higher  in  the  arm  the  position  of  this  funiculus  is 
inconstant  and  variable.  It  may  be  said  that  generally  the  funiculus  to  the 
upper  belly  of  the  flexor  indicis,  the  flexors  digitorum  profundus  and  poUicis 
longus  lies  along  the  dorsal  ulnar  border,  while  the  funiculus  for  the  pronator 
teres  and  flexor  carpi  radialis  lies  ventral  and  in  the  middle  of  the  nerve  trunk 
in  the  upper  part  of  the  arm,  whereas  in  the  lower  third  the  latter  funiculus  lies 


MEDIAN   NERVE 


333 


on  the  radial  and  ventral  border.     The  general  relation  of  these  funiculi  should 
be  remembered  in  operative  procedures  on  the  median  nerve  in  this  region. 


Lint, 
cutaneous 


Ulnar  N.    , 


^lealanN.-'"   /fw^fii 


IjUJ^wHO: 


f\\ 


-4 


Pectora-Ks-- 

mai.M. 


.4 


i 

A;. 


Ulnar  1 


.=2i' 


-MeaiduN. 


BicepsM, 


Fig.  140. — Exposure  of  the  median  and  ulnar  nerves  below  the  pectoralis  major.     The  nerves  are 

seen  passing  into  dense  scar  tissue. 


Exposure  al  the  Elboic. — In  order  to  have  adequate  exposure  of  this  import- 
ant part  of  the  median  nerve  the  humeral  head  of  the  pronator  teres  is  cut  as 


334       SURGICAL    AND     MECHANICAL     TREATMENT    OF    PERIPHERAL    NERVES 

close  as  possible  to  its  origin  and  reflected  upward  and  lateral,  care  being  taken 
to  avoid  injury  to  muscular  branches  which   are  given  off  from  the  median 


FL- 


UlT^ArN. 


Int. 

N. 


MediexnN.    / 
/ 


Q 


To  rev  ^n 


1.^ 


^cM'^^v^*-"^^ 


Fio.   141. — Same  as  Fig.  140.     Dissection  carried  a  stage  farther.     Note  the  foreign  body  in  the  scar. 

nerve  in  this  position.  (See  Fig.  144.)  Before  cutting  the  muscle  a  mattress 
suture  is  passed  to  obtain  hemostasis  from  the  cut  surface  and  to  facilitate 
suture.     In  following  the  nerve  farther  into  the  forearm,   the  fibers  of  the 


MEDIAN    NERVE 


335 


llexor  digitorum  sublimis  are  split  in  the  direction  of  their  course,  since,  because 
of  its  radial  origin,  this  muscle  at  this  level  cannot  be  retracted  mediahvard  to 


Fig.   142. — Same  as  Fig.  140.     The  ulnar  nerve  has  united  with  the  central  stump  of  the  internal 
cutaneous  in  place  of  its  own  central  stump. 

open  the  fascial  plane  between  the  llexor  digitorum  suldimis  and  flexor  digi- 
torum profundus.  Injuries  to  the  median  nerve  at  this  level  offer  the  greatest 
dit'liculty  to  successful  repair,  since  the  nerve  trunk  as  well  as  the  branches  them- 


336      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

selves  may  be  involved.     In  order  to  save  these  branches  careful  dissection 

\ 


Ulrv&r 


rector  au  5 
mcwi.  Ti . 


Fig.  143. — Same  as  Fig.  140.  The  ulnar  connection  with  the  central  end  of  the  internal  cutane- 
ous nerve  has  been  severed  and  the  two  ends  of  the  ulnar  nerve  have  been  sutured.  The  ends  of  the 
median  nerve  could  not  be  brought  together,  necessitating  a  nerve  graft.  The  central  ends  of  the 
internal  and  lesser  internal  cutaneous  nerves  have  been  used  as  grafts  for  the  median  nerve. 

is  demanded  as  well  as  great  conservatism  in  handling  the  isolated  branches; 
either  reuniting  the  branches  or  suturing  them  into  the  nerve  trunk,  or,  if  the 


MEDIAN    NERVE 


337 


injury  be  near  the  point  of  entrance  into  the  muscles  they  may  be  implanted 
directly  into  one  or  two  of  the  muscles. 

Because  of  the  funicular  arrangement  in  certain  levels  a  cable  graft  may  be 
done  so  as  to  reunite  each  individual  funiculus,  thus  securing  better  down- 
growth.     Crossing  of  the  funiculi  at  this  level  is  not  apt  to  be  overcome  since 


Fig.  144. — Exposure  of  the  median  nerve  at  the  elbow.  Complete  interruption  of  the  median 
nerve  with  extensive  scar  involving  the  nerve  at  the  point  where  branches  are  given  off  and  the 
branches  themselves. 


the  nerve  pattern  is  already  fixed  and  branches  given  off  here  cannot  receive 
additional  fibers  from  the  nerve  trunk  as  would  be  the  case  in  suture  at  higher 
levels.  For  this  reason,  lesions  at  this  level  offer  a  poor  prognosis  due,  both  to 
lixation  of  the  nerve  pattern  and  to  the  fact  that  the  branches  themselves  may 
be  irreparably  damaged.  In  estimating  the  percentage  and  degree  of  recovery 
in  operations  upon  the  median  nerve,  the  level  of  the  injury  on  the  nerve  trunk 
must  be  taken  into  consideration,  for  the  prognosis  is  always  more  favorable  in 


338      SURGICAL    AND    MECHANICAL     TREATMENT     OF    PERIPHERAL  NERVES 

suture  above  the  lower  third  of  the  arm  and  below  the  upper  third  of  the 
forearm. 

Exposure  at  the  Wrist. — Here  the  nerve  is  readily  found  by  an  incision 
along  the  ulnar  border  of  the  flexor  carpi  radialis,  between  the  tendon  of  this 


Fig.   145. — Complete  interruption  of  the  median  nerve  with  connective  tissue  continuity  of  the 

uhiar  nerve. 


muscle  and  that  of  the  palmaris  longus  and  beneath  the  latter.  From  this 
position  it  may  be  followed  into  the  palm  beneath  the  anterior  annular  ligament, 
and  between  the  tendon  of  the  flexor  digitorum  sublimis  and  flexor  poUicis 
longus.     In  the  lower  third  of  the  forearm,  the  motor  funiculus  for  the  muscles 


MEDIAN    NERVE 


339 


of  the  thenar  eminence  lies  along  the  radial  side  and  on  the  ventral  surface  of 
the  nerve,  so  that  in  suture  of  the  median  nerve  at  this  level  particular  attention 
should  be  paid  to  this  side  of  the  nerve. 

Occasionally,  when   the  radial  artery  is  absent  the  arteria  comes  nervi 


yinir  K.  transpojed 

Fa-tty  flap 
'covering  bear 


l-'iG.    146. — Same  as  Fig.  145.     Transposition  of  tlie  ulnar  nerve  with  suture  of  both  the  ulnar  and 
median  nerves.     .\  flap  of  fat  has  been  passed  beneath  the  nerves  to  cover  scar  tissue. 


mediani  takes  its  place,  and  may  be  found  in  the  forearm  as  a  large  vessel  on 
the  median  nerve. 

Cross  Suture  of  Superficial  Radial  and  Median  Nerves.— In  certain  cases 
in  which  it  is  impossible  to  perform  end-to-end  suture  at  the  wrist  and  a  nerve 


540       SURGICAL    AND    MECHANICAL    TREATMENT     OF    PERIPHERAL    NERVES 


Flex.cArp> 


Fig.  147. — Complete  severance  of  the  median  nerve  below  the  pronator  teres.  Note  the 
extensive  loss  of  substance  and  large  central  bulb.  After  resecting  to  normal  looking  funiculi  on 
both  the  central  and  distal  ends  1 1  cm.  intervened  between  the  ends,  which  was  bridged  by  a  cable 
transplant. 


MEDIAN    NERVE  341 

graft  is  deemed  inexpedient,  cutaneous  innervation  of  the  hand  may  be  obtained 
by  crossing  the  central  end  of  the  superficial  radial  ner\e  to  the  distal  end  of  the 
median.  Harris  (1920)  obtained  complete  return  of  sensation  by  this  pro- 
cedure. The  median  area  of  sensation  is  extremely  important,  involving 
that  part  of  the  hand  used  most  in  gaining  atferent  impressions.  With 
sensation  lost  the  hand  is  subject  to  a  great  variety  of  insults  from  heat, 
cold,  or  blows  which  may  lead  to  severe  ulceration  and  even  sloughing  of  the 
lingers;  this  is  particularly  true  of  the  index  finger.  The  possibility  of  regaining 
sensation  in  the  palm  more  than  justifies  this  procedure. 

The  radial  nerve  is  exposed  over  the  dorsal  surface  of  the  radius  at  the 
wrist  between  the  tendons  of  the  supinator  longus  and  extensor  carpi 
radialis  longus  and  traced  to  the  base  of  the  index  finger  where  it  is  cut. 
It  is  then  passed  through  a  tunnel  beneath  the  skin  to  the  volar  surface 
over  to  the  previously  exposed  median  nerve  and  end-to-end  suture  is  then 
performed. 

Comment. — Prognosis  for  median  nerve  regeneration  is  not  as  satisfactory 
as  for  musculospiral,  yet  more  hopeful  than  in  ulnar  injuries.  The  fact  that  the 
nerve  supplies  in  the  main  relatively  large  muscles  and  but  a  few  small  ones 
(thenar  group)  may  contribute  to  this.  Large  muscles  generally  have  a  large 
nerve  supply  and  consequently  they  may  lose  a  number  of  their  neuraxes  with- 
out appreciable  difference  in  function.  The  prognosis  is  better  for  suture  in 
the  arm  and  in  the  middle  of  the  forearm  than  at  the  elbow  or  wrist.  The  finer, 
morphological  arrangement  of  the  nerve  trunk  may  account  in  a  measure 
for  this  difference,  since  in  both  the  arm  and  the  middle  portion  of  the  forearm 
the  median  nerve  contains  fewer  and  larger  funiculi.  At  some  levels  but 
two  large  funiculi  are  to  be  seen,  while  at  the  elbow  and  again  at  the  wrist  the 
funiculi  are  smaller  and  more  numerous,  hence  distortion  of  the  nerve  pattern 
is  more  apt  to  occur  at  these  latter  levels.  As  has  already  been  mentioned, 
in  the  chapter  on  funicular  anatomy,  injuries  in  a  nerve  trunk  near  levels  at 
which  branches  are  to  be  given  off,  give  less  favorable  results,  since  the  funicular 
anatomy  at  these  points,  being  more  or  less  fixed,  additional  contributions  to 
(he  ner\-e  branches  are  prevented. 

In  regeneration,  returning  function  in  muscle  groups  occurs  in  accordance 
with  the  principle  already  laid  down.  The  nearer  the  lesion  to  the  spinal  cord 
the  greater  is  the  power  of  regeneration  with  relatively  more  rapid  return. 
Muscle  groups  nearest  the  level  of  the  lesion  are  usually  restored  earliest.  (See 
("hart  XII   XI\'.)      'I'his  latter  rule,  however,  does  not  always  hold  true  since  dis- 


342       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


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MEDIAN    NERVE  345 

tortion  of  thu  pattern  may  take  place  and  regeneration  appear  tirst  in  groups 
more  distant. 

REFERENCES 
AuERBACH,  S.  and  Brodnitz:  Neurofibrom  des  N.  ulnaris  Oberarm:  Exstirpation,  Heilung, 

Mitt.  a.  d.  Grenzgeb.  d.  med.  u.  Chir.,  v.  21 :  1910,  p.  589. 
Bernhardt,  M.:  Beitrag  zur  Pathologic  dcr  Medianuslahmungen,  Neurol.  Zentralbl.,  v. 

16:  1897,  p.  626. 
Bonnet,   P.:  De  la  deviation  en  valgus  dc  L'avant  bras  dans  les  paralysies  associees  du 

median  et  du  cubital,  Lyon  Chir.,  v.  16:   1019,  pp.  631-636. 
BoRCHARDT,   M.    and  Wjasmexski:  Dcr  Nervus  Medianus,  Beitr.  z.  klin.  Chir.,  v.  107: 

I9i7>  P-  553- 
Brandes,  M.:  Zur  Ueberbriickung  von  Nervendefekten  bei  gleichzeitiger  Ulnaris-und  ]\Ie- 

dianus  Verletzung,  Deutsch.  Ztschr.  f.  Chir.,  v.  153:   1920,  pp.  62-69. 
Brouwer,    B.:    The   significance   of   phylogenetic    and  ontogenetic  studies  for  the  neuro- 
pathologist. Jour.  Nerv.  &  Ment.  Dis.,  v.  51:  February,  1920,  p.  113. 
CRUVEiLmER,  J.:  Traite  d'Anatomie  Descriptive,  4  vols.,  Labe,  Ed.  3,  1851-52,  Paris. 
DujARiER,  Ch.:  Paralysie  du  nerf  median  souleve  par  le  fragment  superieur  d'une  fracture 

de  I'e.xtremite  inferieure  d  I'humerus.  Intervention,  Guerison.,  Bull,  et  mem.  Soc.  de 

chir.  de  Par.,  v.  46:  1920,  p.  795. 
Fere,  Ch.:  Traite  filementaire  d'Anatomie  Medicale  du  Systeme  Nerveux,  A.  Delahaye  et 

Lecrosnier,  Paris,  1886. 
Frohse,  F.  and  Frankel,  M.:  Die  Muskeln.  des  menschlichen  Armes,  (Jena,  1913)  m, 

Bardeleben  Handbuch  d'Anat.  d.  Menschen,  v.  2:  sect.  2  part  2,  1913. 
Gierlich:  Ueber  tonischen  Kontrakturen  bei  Schussverletzungen  der  peripheren  Nerven, 

specialle  des  Ulnaris  und  Medianus,  Deutsch.  Ztschr.  F.  Nervenh.,  v.  63:  1918-19, 

p.  145-160. 
Goldmann,  E.:  2.  Ueber  das  Fehlen  von  Funktionsstoerungen  nach  der  Resektion  von  per- 
ipheren Nerven,  Beitr.  z.  klin.  Chir.,  v.  51:  1906,  p.  183. 

Beitrag,  zu  derLehre  von  den  Neuromen,  Beitr.  z.  klin.  Chir.,  v.  10:  1893,  p.  13. 
Gruber,  W.:  Ueber  die  Verbindung  des  Nervus  medianus  mit  dem  Nervus  ulnaris  am 

Unterarme  des  Menschen  und  der  Saugethiere,  Archiv.  f.  Anat.,  1870,  p.  501. 
Halipre,  a.:  D'une  cause  d'erreur  dans  I'appreciation  de  I'importance  des  lesions  du  nerf 

cubital  aubras   (M.   A.    Societe  de   Neurologic  de  Paris)  Rev.  Neurol.,  v.  24:  1917 

p.  236. 
Harris,  R.  I.:  An  operation  for  the  relief  of  median  anesthesia,  J.  Orthop.  Surg.,  v.  2: 

No.  9,  Sept.,  1920,  p.  519. 
Kramer,  F.:  Schussverletzungen  peripherer  Nerven,  Monatschr.  f.  Psychiat.  u.  Neurol., 

V.  39:  1916,  p.  1-19. 
Ranschberg,   p.:  Ueber  klinische   Untersuchung,   operative  Biopsie  und  Heilerfolge  bei 

unfrischen  und  veralteten  Fallen  von  Schussverletzungen  der  peripheren  Nerven,  Beitr. 

z.  klin.  Chir.,  v.  loi:   1916,  p.  521. 


346      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Remak,   E.:  Zur   vicariirenden    Function   peripherer   Nerven   des   Menschen,    Berl.   klin. 

Wchnschr.,  v.  ii:  1874,  pp.  601-615. 
RuGE,  G.:  Beitrage  zur  Gefiisslehre  des  Menschen,  INIorphologisches  Jahrbuch,  v.  9:  1883- 

84,  P-  P-  3^0. 

Spielmeyer,  W.:  Ueber  Nervenschussverletzungen,  Ztschr.  f.  d.  ges  Neurol,  u.  Psychiat., 
V.  29:  191S,  p.  416. 

Stopford,  J.  S.  B.:  The  results  of  secondary  suture  of  peripheral  nerves,  Brain,  v.  43: 
pt.  I,  1920,  p.  I. 

Thomson,  A.:  Third  annual  report  of  the  committee  of  collective  investigation  of  the  x^na- 
tomical  Society  of  Great  Britain  and  Ireland  for  the  year  1891-92,  J.  Anat.  &  Physiol., 
V.  27:  1892-93,  p.  183. 

Verchere,  F.:  Note  sur  I'innervation  des  muscles  flechisseurs  communs  des  doigts;  anas- 
tomose du  nerf  median  et  du  nerf  cubital,  Union  med.  v.  35:  ser.  3,  1883,  p.  205. 


CHAPTER  XV 
ULNAR  NERVE 

Anatomy. — The  ulnar  nerve  arises  from  the  inner  cord  of  the  brachia 
plexus  and  is  formed  by  fibers  derived  jirincipally  from  the  ventral  divisions 
of  the  eighth  cervical  and  first  thoracic  roots,  occasionally  also  fibers  from 
the  seventh  cervical,  which  usually  pierce  the  inner  head  of  the  median  to 
join  the  ulnar.  The  ulnar  nerve,  composed  of  ventral  branches,  supplies 
\entral  musculature  on  the  ulnar  or  postaxial  border  of  the  forearm,  and  all  thel 
intrinsic  muscles  of  the  hand  with  the  exception  of  the  abductor,  opponens 
and  flexor  poUicis  brevis  (superficial  head). 

Course. — The  ulnar  nerve  lies  internal  to  the  median  nerve  and  axillary 
artery  between  the  latter  and  the  axillary  vein,  passing  under  the  vein  when  the 
arm  is  in  abduction.  Internal  to,  and  on  the  nerve  in  the  axilla,  are  the  internal 
and  lesser  internal  cutaneous  nerves.  The  ulnar  nerve  leaves  the  axilla  beneath 
the  pectoralis  major  muscle,  lying  upon  the  teres  major  and  latissimus  dorsi 
tendons  and  in  this  region  is  in  close  proximity  to  the  musculospiral  nerve, 
lying  slightly  ventral  ancl  medial  to  the  hitter.  As  the  ulnar  nerve  descends 
in  the  arm  it  maintains  its  position  medial  to  the  median  nerve  and  brachial 
arterj' ,  lying  upon  the  medial  intermuscular  septum  which  separates  it  from 
the  triceps  muscle.  Slightly  above  the  junction  of  the  middle  and  lower  thirds 
of  the  arm  the  ulnar  nerve  separates  from  the  neurovascular  sheath  and 
j)ierces  the  medial  intermuscular  septum  to  pass  dorsal  to  the  medial  condyle. 
In  this  portion  of  its  course  it  lies  superficially  in  the  fibers  of  the  triceps 
muscle  with  the  inferior  profunda  artery  in  front  of  the  nerve. 

About  4  cm.  above  the  medial  condyle  the  nerve  leaves  its  muscular 
bed  to  enter  the  groove  behind  the  humerus  where  it  is  held  in  place  by  an 
aj)oneurotic  expansion  extending  from  the  medial  condyle  to  the  olecranon. 
This  aponeurosis  is  made  up  of  both  trans\'erse  and  longitudinal  fibers,  the 
remains  of  a  rudimentary  muscle,  the  epitrochleo-anconaeus,  to  which  the  ulnar 
nerve  has  given  a  branch.  A  bursa  has  been  described  beneath  the  nerve 
separating  it  from  the  internal  lateral  ligament,  which  facilitates  free  move- 
ment of  the  nerve  in  flexion  and  extension  of  the  forearm.  The 
nerve   gains   entrance    to  the  forearm  through  the  two  heads  of  the  flexor 

.S47 


34^       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

carpi  ulnaris  muscle.  In  rare  instances  the  nerve  may  pass  not  behind  but 
in  frojil  of  the  medial  condyle  and  enter  the  flexor  carpi  ulnaris  through  a 
cleft  in  this  muscle  (Gruber,  1867).  As  the  ulnar  nerve  Hes  between  the  two 
heads  of  the  flexor  carpi  ulnaris  and  in  the  ulnar  groove  of  the  medial  condyle 
the  posterior  ulnar  recurrent  artery  and  vein  lie  either  lateral  or  dorsal  to  the 
nerve.  The  artery  anastomoses  with  the  inferior  profunda  which  has  de- 
scended with  the  ulnar  nerve  from  above.  Because  of  this  free  anastomosis 
when  cut  both  of  these  vessels  may  cause  troublesome  bleeding  in  this  region 
and  they  should  be  tied  both  distally  and  centrally. 

In  the  forearm  the  nerve  lies  upon  the  flexor  digitorum  profundus, 
within  the  sheath  of  this  muscle,  first  under  the  flexor  carpi  ulnaris,  and  below, 
in  the  cleft  between  the  flexor  carpi  ulnaris  and  the  flexor  digitorum  sub- 
limis.  The  nerve  enters  the  palm  on  the  radial  side  of  the  pisiform  bone,  in  a 
distinct  canal  formed  by  the  anterior  annular  ligament,  and  divides  into  its 
terminal  branches.  At  the  junction  of  the  upper  and  middle  thirds  of  the 
forearm  the  nerve  is  joined  by  the  ulnar  artery  and  venae  comites,  the  vessels 
lying  lateral  to  the  nerve. 

Branches.  In  the  Arm. — No  branches  are  given  off  above  the  lower 
third  of  the  arm.  Approximately  4  to  5  cm.  above  the  medial  condyle 
an  articular  branch  arises  and  also  occasionally  at  a  slightly  lower  level,  a 
motor  branch  for  the  flexor  carpi  ulnaris.     (See  Fig.  148). 

In  the  Forearm. — Motor  branches  are  given  off  for  the  flexor  carpi  ulnaris 
and  the  ulnar  part  of  the  flexor  digitorum  profundus.  These  muscles  are 
supplied  by  two  sets  of  fibers.  The  upper  set  for  the  flexor  carpi  ulnaris 
enters  the  muscle  as  the  nerve  lies  between  the  two  heads  of  origin  of  this 
muscle,  and  the  lower  set  arises  from  the  main  nerve,  or  from  the  branch  to 
the  flexor  digitorum  profundus,  and  enters  the  muscle  in  the  middle  third. 
The  branches  to  the  flexor  digitorum  profundus  are  larger  than  those  to  the 
flexor  carpi  ulnaris,  both  are  given  off  from  the  nerve  trunk  in  the  upper  third 
and  pass  immediately  to  the  flexor  digitorum  profundus  and  descend  upon  it. 
The  dorsal  cutaneous  branch  is  given  off"  in  the  middle  third  of  the  forearm  and 
passes  beneath  the  flexor  carpi  ulnaris  tendon  to  reach  the  dorsum  of  the 
forearm  and  hand.  In  place  of  arising  at  about  the  junction  of  the  middle  and 
lower  thirds  this  branch  may  be  given  off  as  high  as  the  medial  condyle  (Henle, 
1876)  or  as  low  as  the  styloid  process  (Krause,  1861)  and  may  be  as  large  as 
the  main  trunk,  so  that  the  latter  may  be  thought  the  branch.  Arising  from 
the  ulnar  nerve  in  the  middle  third  of  the  arm  is  a  slender  branch  to  the  ulnar 


ULNAR    NERVE 


349 


Fig.  148. — Ulnar  nerve.  Surface  projection,  i,  .Vrlicular  branch  to  elbow  joint;  2,  branch  to 
De.xor  carpi  ulnaris;  3,  branch  to  inner  half  of  flexor  digitorum  profundus;  4,  dorsal  cutaneous  branch; 
5,  palmar  cutaneous  branch;  6,  muscular  branch  to  hypothenar  group;  7,  muscular  branch  to  inter- 
ossei,  inner  lumbricalcs,  adductor  pollicis,  obliquus  and  transversus,  fle.xor  poUicis  brevis  (deep  head). 


350      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


M.  triceps,  caput  mediale 


Epicondylus  medial: 


Olecranon- 


M.  pronatoi 
teres 


R.  superior 
anterior 


R.  accessori 


Septum  iater- 

musculare 

mediale 


R.pro  m.  flexore 
digitonim 
prof  undo 


M.  flexor  digitorum 
profundus 


yi.  flexor  digitorum 
sublimis 


M.  flexor  digitorum  sub- 
limis, caput  radiale  pro 
digito  III 


N.  mediani 


.v.  radialis 


Fig.   149. — Flexor    carpi    ulnaris   muscle  showing  variation  in  innervation.   (Frohse  and  Frankel.) 


ULNAR    NERVE 


351 


artery,  which  accompanies  the  artery  to  the  palm  of  the  hand  and  anastomoses 
with  one  of  the  terminal  digital  branches  of  the  median.  In  the  lower  third 
of  the  forearm  a  cutaneous  branch  is  given  off  which  supplies  the  skin  of  the 
lower  third  of  the  forearm  as  far  as  the  hypothenar  eminence. 

At  the  Wrist. — The  nerve  divides  into  two  main  branches,  a  superficial, 
which  lies  internal  and  adjacent  to  the  pisiform  bone  and  crosses  the  flexor 
digiti  quinti  brevis;  and  a  deep  branch  which  lies  external  and  passes  beneath 
this  muscle.     The  superficial  branch  is  mainly  sensory  but  supplies  also  the 


M.  ioterosseus 
dorsalis  111 


I  metacirp.ilc  III 


metac.irp.-ile  11, \\ 

rcscctiim 


f.  extensor  carpi 
r.idiuli8  brevis 


Os  capitatuni 


M.  extensor  pollicis  longus 


M.  extensor  pollicis  brevis 


M.  interosseus  volaris  I 


M.  abductor  pollicis  longus 
M.  extensor  carpi  radialis  longus 


and  Friinkel.) 

small  pal  maris  brevis  muscle  which  lies  in  the  skin  of  the  hypothenar  eminence, 
The  deep  branch  passes  between  the  origin  of  the  flexor  digiti  quinti  and  the 
abductor  digiti  quinti  muscles,  curves  radialward  and  lies  upon  the  interosseous 
muscles  to  terminate  in  supplying  the  deep  portion  of  the  flexor  brevis  pollicis 
where  it  forms  a  delicate  anastomosis  with  median  nerve  fibers.  (See  Fig.  150.) 
Funicular  Anatomy. — The  funiculus  for  the  flexor  carpi  ulnaris  and  flexor 
profundus  may  be  identified  in  the  ulnar  nerve  4  to  5  cm.  above  the  medial 
londyle  lying  in  the  medial  and  dorsal  ]iart  of  the  nerve.  (See  Fig.  151.) 
Occasionally  this  funiculus  may  be  separated  from  the  nerve  for  some  distance 


352       SURGICAL    AND    MECHANICAL^  TREATMENT    OF    PERIPHERAL    NERVES 

n 

Ulnar  border 


of  hand 


Wrist 


Communication teiween.  ..—.'-r^ 
median  6  ulnar  N.         /  m 


Communication  of 
mediaiiN  to 
deep  br  of 
Ulnar  N. 
Hntrinsic  musdesj 


Fig.  151. — Macerated  dissection  of  the  left  ulnar  and  median  nerves  showing  two  types  of 
communication  between  these  nerves.  The  bundles  of  the  ulnar  nerve  have  been  dissected  free  and 
separated.  D,  Short  communication;  £,  long  communication  to  the  deep  branch  of  the  ulnar  (in- 
trinsic muscles  of  the  hand);  \a,  branch  to  pronator  teres,  humeral  head,  upper  part  and  lower  part  of 
muscle;  2a,  branch  to  superior  belly,  fle.xor  indicis  sublimis;  2J,  branch  to  palmaris  longus;  3,  branch 
to  flexor  digitorum  sublimis,  3d,  4th  and  5th  fingers;  43,  branch  to  fle.xor  digitorum  profundus,  3d, 
4th  and  5th  fingers;  46,  branch  to  flexor  pollicis  longus;  4c,  anterior  interosseous  nerve;  5,  branch 
to  deep  belly  of  flexor  indicis  sublimis;  6a  and  6i,  branch  to  fle.xor  carpi  ulnaris;  7,  dorsal  cutaneous 
branch  of  the  ulnar  nerve;  8,  palmar  cutaneous  branch  of  the  ulnar  nerve,;  9,  deep  muscular  branch 
of  the  ulnar  nerve;  10,  superficial  branch;  11,  palmar  cutaneous  branch  of  the  median  nerve.  (After 
Borchardt   and  VV'jasmenski.) 


ULNAR    NERVE  353 

above  the  condyle  and  have  a  relatively  long  extrancural  course.  The  funiculi 
in  the  ulnar  nerve  are  small  and  numerous  except  immediately  above  the  elbow 
and  above  the  wrist  where  the  funiculi  unite  into  three  or  four  large  bundles. 
These  levels  are  just  above  those  at  which  branches  are  given  off,  and  it  is 
here  that  internal  nerve  plexuses  are  found. 

Deformity. — The  deformity  varies  according  to  the  site  of  the  injury. 
In  complete  ulnar  nerve  lesions  above  the  elbow  the  postaxial  border  of  the  fore- 
arm is  slightly  concave  due  to  the  disappearance  of  the  contour  formed  by  the 
flexor  carpi  ulnaris  muscle.  Flexion  of  the  wrist  is  weakened  and  adduction  is 
lost,  and  on  attempt  to  flex,  the  wrist  turns  slightly  toward  the  radial  side. 
The  hand  deformity  is  characteristic  with  the  fifth  and  fourth  fingers  extended 
at  the  metacarpophalangeal  joints  and  flexed  at  the  interphalangeal.  The 
third  finger  also  tends  to  assume  this  position  but  to  a  less  extent.  The  thumb 
is  drawn  into  the  same  plane  as  the  other  metacarpal  bones  and  all  interspaces 
are  distinctly  hollowed.  Due  to  atrophy  of  the  interosseii  the  hand  is  narrow, 
soft  and  flexible  and  both  the  longitudinal  and  transverse  arches  are  lost.  The 
hypothenar  and  the  thenar  muscles  show  marked  wasting  and  neither  opponens 
action  nor  abduction  of  the  little  linger  can  be  accomplished.  The  thumb  is 
unable  to  adduct,  or  grasp  objects  in  the  first  interspace,  but  instead,  in  attempt- 
ing thus  to  grasp,  the  distal  phalanx  of  the  thumb  is  flexed  and  the  object  held 
against  the  proximal  phalanx  of  the  index  by  action  of  the  flexors  in  place  of 
the  adductors  of  the  thumb.  This  is  a  striking  diagnostic  sign  described  by 
Froment  (1915).  Paralysis  of  the  interosseii  prevents  flexion  of  the  fingers 
at  the  metacarpophalangeal  joints  without  flexion  at  the  interphalangeal  joints, 
nor  can  the  distal  two  phalanges  be  extended. 

Mechanical  Treatment. —  Contracture  at  the  proximal  interphalangeal 
joints  of  the  fourth  and  fifth  fingers  with  subluxation  is  apt  to  occur  unless  the 
fingers  aresplinted.  Sphnts  shown  in  Figs.  152  and  153  will  be  found  satisfactory. 
Splinting  should  not  be  done  unless  accompanied  by  mobilization,  since  the 
tendency  to  fixation  of  the  proximal  interphalangeal  joints  is  marked.  When 
this  has  occurred  function  may  be  limited  even  if  regeneration  does  take  place. 
In  neglected  cases  these  contractures  may  be  overcome  by  a  splint  such  as  is 
shown  in  Fig.  154,  which  can  be  adjusted  to  hold  the  distal  two  phalanges  in 
constant  extension  and  pulls  the  proximal  phalanges  in  the  opposite  direction. 
This  apparatus  is  a  modification  of  the  author's  dorsal  cock-up  splint  using  a 
Robert  Jones  glove  and  allows  a  great  variety  in  the  treatment  of  contractures 
of   the  fingers  from  cither  ulnar  or  median  nerve  injuries.     The  small  intrin.sic 


354       SURGICAL    AND     MECHANICAL     TREATMENT    OF    PERIPHERAL    NERVES 


Fig.  152. — Splint  for  ulnar  paralysis  applied.     (Buerki, 

Psychiatry,  1920.) 


.\rchives  of  X'eurology  and 


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Fig.  153. — Splint  for  ulnar  paralysis.  It  is  made  of  galvanizediron,  padded  withfelt.'  Thefelt 
is  stuck  to  the  iron  with  sealing  wax.  Four  copper  rivets  hold  the  straps  in  place.  The  whole  is 
then  fitted  to  the  ulnar  side  of  the  hand.  A  forward  bend  of  the  finger  extensions  corrects  the  tend 
ency  to  hv^erextension.  The  finger  pieces  made  of  galvanized  iron  padded  and  surrounded  with 
adhesive  tape  are  held  to  the  main  splint  with  rubber  bands  which  produce  the  required  extension. 
(Buerki,  Archives  of  Neurology  and  Psychiatry,  19:^0.) 

'  This  splint  may  be  made  of  aluminum  and  is  then  much  lighter. 


ULNAR   NERVE 


355 


muscles  of  the  hand  very  quickly  undergo  regressive  changes  and  may  loose  per- 
manently the  finer  specialized  movements  of  which  they  are  capable.  Hence, 
during  the  intervals  both  before  and  after  operation  special  effort  should  be  made 
to  maintain  the  nutrition  of  these  muscles  by  frequent  use  of  the  slow  sinusoidal 
current  and  the  Zander  finger  apparatuses.  The  latter  will  be  found  of  great 
help  in  maintaining  normal  range  of  motion  and  preventing  contractures. 


Fio.  154. — Splint  to  overcome  contracture  aliout  the  metacarpophalangeal  and  interphalangeal 
joints.  Aluminum  dorsal  cock-up  splint  with  perforated  shelf  to  which  strings  from  fingers  of  glove 
are  attached  permitting  constant  pressure  to  be  e.xerted.  The  direction  of  the  perforated  shelf  may- 
be changed  to  meet  the  requirements  of  each  case,  or  another  shelf  may  be  added  above  to  permit 
a  counter  pull.     \n  infinite  variety  of  contractures  may  be  treated  by  this  appliance. 


Exposure  of  the  Ulnar  Nerve.  /;;  the  .{.villa.  The  ulnar  nerve  in  this 
region  is  exposed  in  the  same  manner  as  has  alreaily  been  described  for  the  other 
nerves  of  the  axilla.  (See  Fig.  127.)  The  nerve  at  this  level  is  rarely  injured 
alone  but  usually  in  combination  with  either  the  median  or  the  musculospiral — ■ 
more  frequently  with  the  latter. 

In  the  Ann.  Position  oj  the  Patient. — The  arm  is  abducted  and  at  right 
angles  to  the  body.  The  elbow  is  raised  ujion  a  sand  bag  so  that  the  triceps 
hangs  down  unsu[)i)(irted.     If  the  arm  is  allowed  tn  rest  on  the  table  the  triceps 


356       SURGICAL    AND    MECHANICAL     TREATMENT     OF    PERIPHERAL    NERVES 

is  pushed  toward  the  biceps  and  the  space  between  those  two  muscles  is  more 
or  less  obliterated,  concealing  the  nerve. 

Incision  is  made  along  the  Hne  of  the  great  vessels,  for  exposure  of  the 
upper  two-thirds  of  the  nerve,  and  for  the  lower  third,  along  a  line  drawn  from 


Ulnar  N. transposed 


Fig.  155. — Transposition  of  the  ulnar  nerve.     The  deep  fascia  is  cut  in  a  curve  so  as  to  be  able 

to  turn  it  over  the  nerve  after  transposition. 
Fig.  156. — The  ulnar  nerve  transposed  in  front  of  the  condyle  and  held  in  its  new  position  by  the 

flap  of  deep  fascia  reflected  over  it. 


the  junction  of  the  middle  and    lower  thirds  of  the  nerve  to  the  olecranon 
process. 

Exposure. — In  its  upper  two-thirds  the  nerve  is  readily  identified  lying 
internal  to  the  brachial  artery,  separated  from  it  by  the  internal  of  the  two 
venas  comites  which  accompany  the  brachial  artery.     The  internal  vena  comes 


ULNAR    NERVE  357 

is  the  larger  and  terminates  higher  up  in  the  basilic  vein.  In  its  middle  and 
lower  thirds  the  ulnar  nerve  is  accompanied  on  its  medial  border  by  the  col- 
lateral ulnar,  a  branch  of  the  musculospiral  nerve.  In  the  lower  third  the  nerve 
will  be  found  superticial  within  the  iibers  of  the  triceps  muscle  accompanied 
by  the  inferior  profunda  artery  which  may  cause  troublesome  bleeding  unless 
isolated  and  secured  not  only  above  but  below,  since  it  receives  from  below 
the  collateral  circulation  from  the  ventral  and  dorsal  ulnar  recurrent 
arteries. 

At  the  Elbow. — This  exposure  is  frequently  necessary  both  for  transposition 
of  the  nerve  to  the  front  of  the  condyle  when  the  nerve  ends,  elsewhere  severed, 
cannot  otherwise  be  brought  together,  and  when  the  nerve  on  account  of  angula- 
tion from  fractures  at  the  elbow  is  subject  to  repeated  traumatism.     (See 

Figs-  155.  156.) 

Incision. — The  incision  is  made  from  the  junction  of  the  middle  and  lower 
thirds  of  the  arm,  slightly  curved  with  the  center  crossing  the  medial  border 
of  the  olecranon,  to  the  junction  of  the  upper  and  middle  thirds  of  the  forearm. 
The  anterior  edge  of  the  incision  is  carefully  undermined  in  the  line  of  cleavage 
between  the  deep  and  superficial  fascia,  thus  avoiding  the  veins  within  the 
latter,  for  with  care  the  veins  can  be  saved.     The  flap  must  be  undermined 
forward  as  far  as  the  medial  border  of  the  biceps  tendon,  to  allow  enough  room 
for  the  transposition.     All  bleeding  points  are  secured  and  a  layer  of  gauze 
is  placed  beneath  the  outside  of  the  flap  to  prevent  too  sharp  angulation  of  the 
latter  when  it  is  reflected,  and  the  flap  is  also  covered  on  its  inner  side  by  a 
large  pad  of  moist  cotton.     This  is  maintained  in  place  and  kept  moist;  thus  the 
flap  will  be  well  protected  and  the  tissues  fresh  at  the  close  of  the  operation. 
The  posterior   flap   is  also  undermined  for   2  or  3   cm.   to   expose   the  deep 
fascia  attached  to  the  olecranon.     This  fascia  is  now  cut  in  a  curve  and  dis- 
sected free  from  the  medial  condyle  so  as  to  allow  its  use  to  hold  the  nerve  in 
place  after  transposition.     The  nerve  now  lies  exposed  and  can  be  freed  from 
its  bed  by  sharp  dissection,  care  being  taken  to  safeguard  the  motor  branches 
to  the  flexor  carpi  ulnaris  and  flexor  profundus  which  arise  in  this  region.     The 
articular  branch,  however,  may  be  sacrificed  for  greater  mobilization  of  the 
nerve.     The  line  of  union  of  the  two  heads  of  the  flexor  carpi  ulnaris  is  now 
opened,  the  dissection  being  made  precisely  along  this  line.     In  this  region 
considerable  bleeding  from  the  posterior  ulnar  recurrent  artery  will  be  met. 
If  the  motor  branches  to  the  flexor  profundus  and  flexor  carpi  ulnaris  do  not 
permit  sufficient  mobilization  of  the  trunk  they  may  be  dissected  off,  up  the 


358       SURGICAL    AND    MECHANICAL    TREATMENT    OE     PERIPHERAL    NERVES 

sheath  of  the  ner\'e  for   i   or  2  cm.,  without  injury  to  them  with  consequent 
mobilization  gain. 

After  the  nerve  has  been  transposed  the  surgeon  must  make  sure  that  the 
nerve  course  is  properly  curved  without  sharp  angulations  or  kinks,  especially 
where  it  passes  forward  in  front  of  the  elbow  and  where  it  enters  the  flexor  carpi 
ulnaris  muscle.  The  opening  through  the  intermuscular  septum  above  is  cut 
freely  to  avoid  angulation  at  this  point.  The  fascia  which  has  been  reflected 
from  the  medial  surface  of  the  condyle  is  now  sutured  to  the  deep  fascia  in  front 
far  enough  to  prevent  the  nerve  from  slipping  back  over  the  condyle  and  yet 


1  iij.  1:7.  —Exposure  of  the  ulnar  nerve  at  the  elbow  with  anterior  flap  made  to  permit  trans- 
position. The  line  of  cleavage  between  the  superficial  and  deep  fascia  is  found  and  the  skin  and 
superficial  fascia  are  then  dissected  well  in  front  of  the  condyle  so  that  room  for  transposition  without 
angulation  can  be  obtained. 

sufficiently  loose  to  avoid  constriction  of  the  nerve.  (See  Fig.  156.)  While 
such  a  flap  of  fascia  does  not  contract  as  much  as  a  free  fascial  transplant  some 
contraction  always  takes  place,  which  must  be  reckoned  with. 

In  place  of  reflecting  a  flap  of  fascia  to  prevent  the  nerve  from  slipping,  the 
anterior  undermined  skin  flap  may  be  sutured  along  a  curved  line  about  3  or 
4  cm.  in  front  of  the  medial  condyle  and  medial  to  the  transposed  ulnar  nerve. 
The  sutures  are  passed  through  the  superficial  fascia  of  the  flap  4  cm.  from  its  cut 
margin,  to  the  deep  fascia  below  and  tied.  The  cut  edges  of  the  skin  and  super- 
ficial fascia  of  the  anterior  and  posterior  flaps  are  then  approximated  in  the 
usual  manner.     Smooth  fascial  surfaces  without  bleeding  may  be  obtained  if 


ULNAR    NERVE 


359 


the  anterior  tla[)  has  lieen  reflected  in  the  plane  between  the  superficial  and  deep 
fascia.     Thus  a  smooth  fascial,  scar-free  bed  is  made  for  the  nerve. 

If  transposition  is  done  to  overcome  a  defect  either  the  central  or  the  distal 
end  may  be  transposed,  depending  on  the  site  of  the  injury.  If  the  motor 
branches  to  the  flexor  carpi  ulnaris  and  fle.xor  digitorum  profundus  have  been 
destrc)_\'ed,  or  if  it  is  decided  to  sacrifice  them  in  order  to  obtain  neurotization 
of  llie  more  important  intrinsic  muscles  of  the  hand,  either  or  both  ends  of 
the  ner\e  may  then  be  passed  through  a  tunnel  made  beneath  the  flexor  digi- 
torum sublimis  and  pronator  teres,  upon  the  flexor  digitorum  profundus  muscle. 


Fig.  158. — Transposition  of  the  ulnar  nerve,  same  as  Fig.  157.  The  nerve  has  been  cut  and  a 
silk  suture  passed  through  the  scar  tissue  end.  The  central  end  is  being  drawn  through  between 
tlie  superficial  and  deep  muscles.  It  is  always  best  to  draw  the  nerve  through  before  freshening 
the  ends  and  thus  avoid  trauma  to  the  nerve  tissue. 

(See  Figs.  157  and  158.)  The  nerve  is  freed  the  required  distance  either  above 
or  below  the  elbow  and  a  fine  black  silk  suture  is  placed  on  the  same  border  of 
botii  the  central  and  distal  stumps  so  as  to  permit  identification  of  the  borders, 
thereby  permitting  identification  and  avoidance  of  axial  rotation.  Before  the 
nerve  ends  are  freshened  a  stay  suture  is  passed  through  the  scar  tissue  of  the 
tier\c  end  to  be  transposed.  A  clamp  is  then  passed  from  below  upward,  care 
being  taken  ihal  the  tunnel  is  made  between  the  above-mentioned  muscles  and 
not  through  I  hem.  The  stay  suture  is  now  grasped  by  the  forceps  and  the  nerve 
is  gently  pulled  through  into  its  new  bed.     If  the  motor  branches  to  the  flexor 


360       SURGICAL    AND     MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

carpi  ulnaris  and  flexor  profundus  have  been  deliberately  sacrificed  they  should 
have  been  cut  at  the  point  at  which  they  enter  the  muscle  so  that  after  transposi- 
tion they  may  be  implanted  directly  into  the  muscles  from  which  they  were  cut. 

The  two  nerve  ends  are  now  oriented  so  that  the  silk  identification  sutures 
lie  on  the  same  border  and  the  nerve  ends  are  cut  until  good  cross  sections  are 
seen.  End-to-end  suture  is  then  done.  It  is  important  that  the  nerve 
be  passed  through  the  tunnel  before  the  end  is  freshened.  This  subjects  to  the 
trauma  of  the  pulling  only  the  scar  tissue  which  is  to  be  cut  away. 

If  the  motor  branches  to  the  flexor  carpi  ulnaris  and  flexor  digitorum 
profundus  have  not  been  sacrificed  the  nerve  may  be  transposed  superficial  to 
the  flexor  muscles  instead  of  beneath  them.  This  transposition  brings  about 
i)^  cm.  less  into  the  defect  than  when  the  nerve  is  passed  beneath 
the  muscles.  Some  surgeons  cut  down  through  the  pronator  teres,  flexor 
carpi  radialis,  palmaris  longus  and  flexor  digitorum  sublimis  in  order  to  add 
this  distance.  This  procedure,  to  my  mind,  is  not  desirable.  It  is  better,  if 
this  distance  be  needed,  to  sacrifice  the  twigs  to  the  flexor  carpi  ulnaris  and 
flexor  profundus  digitorum  and  pass  the  nerve  through  a  tunnel  made  beneath 
the  muscles  rather  than  to  cut  the  muscles  and  leave  the  nerve  between  cut 
muscle  fibers.  In  the  presence  oj  an  existing  paralysis  of  one  group  the  function 
of  other  and  sound  muscles  should  not  be  jeopardized  if  it  is  possible  to  avoid 
doing  so. 

If  the  motor  branches  to  the  flexor  carpi  ulnaris  and  flexor  profundus  have 
been  sacrificed  the  flexor  profunds  tendons  to  the  fourth  and  fifth  fingers 
may  be  implanted  into  those  of  the  first  and  second  and  the  palmaris  longus 
into  the  tendon  of  the  flexor  carpi  ulnaris  with  good  functional  result. 

Exposure  in  the  Forearm. — The  incision  is  made  along  the  flexor  carpi 
ulnaris  muscle,  over  the  line  of  the  nerve,  which  lies  between  the  flexor  digitorum 
sublimis  and  the  flexor  carpi  ulnaris,  and  upon  the  flexor  digitorum  profundus. 
If  the  opening  in  the  fascia  is  made  in  the  same  line  as  the  skin  incision  the  knife 
will  cut  down  upon  the  flexor  carpi  ulnaris  muscle  since  the  cleft  between  the 
flexor  digitorum  sublimis  and  the  flexor  carpi  ulnaris  is  farther  lateral.  Con- 
sequently the  deep  fascia  should  be  opened  a  little  more  lateral  than  the  skin 
incision.  The  cleft  between  these  two  muscles  can  usually  be  palpated  better 
than  it  can  be  seen.  The  flexor  carpi  ulnaris  muscle  may  be  readily  identified 
by  the  fact  that  its  tendon  is  well  defined  high  on  its  radial  side,  while  on  the 
ulnar  side  the  fleshy  fibers  extend  to  near  its  insertion.     (See  Figs.  159, 160, 161.) 

The  nerve  in  its  middle  and  lower  thirds  lies  very  close  to  the  ulnar  artery 


ULNAR    NERVE 


361 


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Uln:.rN. 
■Dorsal  cut.  bt 


Uln^r  A.- 


Fig.  159. — Extensive  involvemenl  of  the  ulnar  nerve  in  tiie  middle  of  the  forearm.  Note  the 
large  central  bulb  and  the  dense  scar  tissue  between  the  nerve  ends.  In  this  case  conservative 
treatment  unfortunately  was  followed  for  nearly  eleven  months  with  Tinel's  sign  relied  on  as  evidence 
of  regeneration. 


362       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Ulna^rN. 


Flexor 
pro^u.rvclu.5 


Uln.r  A 


•Doi"5ixl  Cut.tr 


Fig.  160. — Same  as  Fig.  159.  The  nerve  ends  were  freshened  until  normal-appearing  funicuU 
were  encountered.  A  single  stay  suture  held  by  forceps  was  passed.  In  this  manner  the  nerve  ends 
are  steadied  and  gentle  traction  made  by  pulling  on  the  forceps.  By  rotating  the  forceps  the  nerve 
ends  are  rotated  thus  facilitating  suture  of  the  grafts.  One  graft  is  already  sutured  and  a  second  is 
in  place  ready  for  suture. 


ULNAR    NERVE 


363 


anil  internal  to  it.     The  same  fascial  sheath  encloses  the  two  and  includes  them 
in  the  tlexof  digitorum  profundus  sheath.     Because  of  this  proximity  the  nerve 


Uln<.rN. 


\A^U^ 


Fig.  161. — Cable  graft  in  place. 


may    be   so   closely  adherent  to  the  vessel  in  scar  tissue  that  separation  is 
difficult  and  bloodv. 


3^4 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Exposure  at  the  Wrist. — The  incision  is  made  along  the  radial  border  of  the 
flexor  carpi  ulnaris  tendon,  radial  to  the  pisiform  bone  and  into  the  palm  in  the 
direction  of  the  third  interspace.     The  anterior  annular  ligament  is  cut  to  open 


Flexiijitorum 
subtimii  tendon 

Ulnir  A 


Deep  bi 
of  ulnar  N.    , 

Superficial . 
tr.ot  ulnar  N. 


Fig.  162. — E.xposure  of  the  ulnar  and  median  nerves  at  the  wrist  with  suture  of  the  ulnar  and 
liberation  of  the  median.  At  this  point  the  ulnar  nerve  breaks  up  into  its  terminal  branches 
and  each  was  sutured  separately.  A,  shows  sutures  in  place;  B,  sutures  tied  and  nerve  ends 
approximated. 

the  special  compartment  through  which  the  ulnar  nerve  passes.     At  this  point 
the  ulnar  artery  leaves  the  nerve  and  passes  over  the  anterior  annular  ligament. 


ULNAR    NERVE 


365 


The  nerve  here  divides  into  two  terminal  branches;  the  cutaneous;  superficial, 
and  the  deep  motor.  (See  Figs.  162,  163.)  The  opponens  and  abductor  digiti 
quinti  muscles  may  be  cut  at  their  origin  from  the  hook  of  the  unciform  and 
reflected  to  the  ulnar  side  thus  exposing  the  nerve.     If  there  is  any  loss  of  sub- 


FlG.  163. — Division  of  deep  palmar  branch  of  ulnar  nerve  by  machine  gun  bullet.  Resection 
of  end  bulbs  and  end-to-end  suture.  The  inserts  show  the  successive  stages  of  the  operation. 
(Elsberg,  Archives  of  Neurology  and  Psychiatry.) 


stance  end-to-end  union  may  be  very  difficult  to  obtain  even  with  fie.xion  at  the 
wrist  and  extension  at  the  elbow,  since  any  mobilization  of  the  distal  end  is 
hardly  possible.  Due  to  the  relatively  small  size  of  the  nerve  in  this  region  a 
single  nerve  graft  may  be  used,  and  even  though  the  nerve  supply  tothehypothe- 
nar  muscles  be  lost  by  destruction  of  their  nerve  branches,  the  interosseii  may 
still  be  saved  and  \'aluable  function  restored  lo  the  hand. 


366        SURGICAL    AND    MECHAXICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Comment. — Regeneration  of  the  ulnar  ner\-e  following  suture  offers  a 
relatively  poor  prognosis  so  far  as  complete  functional  return  of  the  interosseii 
and  hypothenar  muscles  is  concerned.  Recovery  in  the  flexor  carpi  ulnaris 
and  flexor  digitorum  profundus  takes  place  more  often,  providing  the  injury  to 
the  nerve  trunk  has  not  destroyed  the  nerve  at  the  level  at  which  their  branches 
are  given  off.  The  ulnar  nerve  contains  a  relatively  large  number  of  aft'erent 
fibers  to  supply  muscles  whose  actions  require  an  extremely  precise  proprio- 
ceptive sense  if  finer  movements  are  to  be  accurately  done.  In  man  these  mus- 
cles have  acquired  a  great  range  of  movements  and  functions  that  are  relatively 
new,  and  in  order  for  these  to  be  done  with  precision  synergic  control  and  pro- 
prioceptive sensations  must  be  regained.  The  ulnar  nerve  is  made  up  of 
numerous  small  funiculi  and,  in  suture,  misdirection  of  the  neuraxes  is  more  apt 
to  occur  than  if  the  funiculi  were  larger  and  less  numerous,  although  internal 
nerve  plexuses  may  help  to  rearrange  and  redistribute  the  fibers  within  the 
difi'erent  funiculi.  In  the  ulnar  nerve  there  are  two  main  plexuses,  one  just 
above  the  elbow  and  the  other  above  the  wrist ;  both  situated  immediately  above 
points  at  which  nerve  branches  are  given  off.  It  is  possible  that  poorl}-  shunted 
fibers  may  be  rearranged  in  these  areas  unless  the  injury  is  in  such  a  plexus  or 
immediately  below  it.  Another  cause  of  failure  may  be  rapid  permanent  regres- 
sion of  the  small  muscles  before  regeneration  takes  place,  causing  contractures  of 
a  permanent  nature  unless  carefully  guarded  against.  Even  with  regeneration 
recovery  may  be  very  slow  in  these  small  muscles,  but  functional  return  has  been 
known  to  take  place  after  an  extremely  long  period  of  apparent  failure.  In  two 
of  my  patients  regeneration  did  not  begin  until  twenty-four  months  after  suture 
and  subsequently  they  went  on  to  recovery,  while  Herman-Johnson  (1918)  has 
reported  a  case  in  which  recovery  began  forty  months  after  operation.  It  is 
possible  that  such  delay  may  not  be  due  to  failure  in  nerve  regeneration,  but 
rather  to  failure  in  regeneration  of  the  small  muscles  of  the  hand  wliich  have 
undergone  severe  regressive  changes.     (See  Charts  XV,  XVI.) 

The  ulnar  nerve  is  injured  less  frequently  than  the  musculospiral  to  which 
it  stands  second  on  the  list  of  injuries  of  the  nerves  of  the  upper  extremity. 
Perhaps  the  close  relation  of  the  ulnar  nerve  to  the  bony  parts  of  the  elbow  may 
account  for  this  greater  frequency  of  injury  over  the  median,  for  in  other 
respects  the  two  nerves  are  very  similarly  placed. 

Traumatism  of  Ulnar  Nerve  at  Elbow. — Because  of  its  relationship  to 
the  elbow,  the  frequency  of  fractures  of  the  elbow  in  which  angulation  may 
occur  increases  the  frecjuency  of  ulnar  nerve  traumatism.     Such  traumatism 


ULNAR    NERVE 


367 


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ULNAR    NERVE  369 

may  also  be  due  to  solid  or  cystic  tumors  in  the  region  of  the  medial  condyle. 
In  some  cases  the  ulnar  nerve  shows  no  evidence  of  injury  at  the  time  of  acci- 
dent but  years  later,  twenty,  thirty,  or  according  to  Hunt  (1916),  even  thirty-six 
years  may  elapse  before  any  signs  of  nerve  involvement  appear.  Similar  cases 
have  been  reported  by  Sherren  (i9o8),Mouchet  (1914),  Adson(i9i8)  andSchaller 
(1920).  In  one  case  of  the  author,  signs  of  nerve  involvement  first  appeared 
thirty-two  years  after  fracture  of  the  medial  condyle.  At  first  the  patient  com- 
plains of  tingling  and  numbness  in  the  ])eripheral  cutaneous  distribution  of  the 
ulnar  ncr\'e  and  this  is  followed  by  atrophy  of  the  ulnar  muscles.  With  no  recent 
history  of  trauma  to  the  nerve  the  condition  at  first  may  be  thought  a  syringo- 
myelia or  due  to  a  cervical  rib,  but  a  careful  sensory  examination,  Roentgen  ray 
t)f  the  elbow  and  fuller  history  will  help  to  make  the  differentiation.  At  opera- 
tion the  nerve  may  show  little  gross  anatomical  changes,  but  the  vessels  are 
more  prominent  and  numerous,  and  the  nerve  slightly  thickened  over  a  distance 
of  4  or  5  cm.  But  in  more  severe  cases  the  nerve  shows  a  fusiform  swelling 
with  an  increase  in  the  endoneural  and  perineural  connective  tissue.  Trans- 
position of  the  nerve  to  the  volar  surface  of  the  condyle  will  generally  relieve 
the  condition  eventually.  The  nerve  may  be  injected  with  salt  solution  or  the 
neuroma  slit  longitudinally.  By  transposition  the  constant  trauma  of  the 
nerve  is  prevented  and  even  old  severe  changes  in  the  nerve  trunk  slowly 
improve.  More  rarely  suture  must  be  done.  The  indication  for  suture  should 
be  considered  with  great  caution  and  the  nerve  divided  only  after  making  sure 
thaj:  recovery  will  not  take  place  by  transposition  alone.  The  great  importance 
of  the  ulnar  nerve  to  the  individual  and  its  peculiarities  already  described  make 
conservative  surgical  procedures  more  imperative  than  in  any  other.  Simple 
transposition  should  always  be  given  a  fair  trial  when  possible  before  perform- 
ing section  and  suture. 

In  some  individuals  the  medial  condyle  normally  is  little  prominent  and 
the  groove  for  the  ulnar  nerve  is  relatively  shallow  so  that  subluxation  of  the 
nerve  may  constantly  occur  and  eventually  give  rise  to  clinical  signs  of  nerve 
injury,  ("ollinet  (1896)  found  that  luxation  of  the  ulnar  nerve  occurred 
congenitally  in  3  %  of  five  hundred  individuals  examined,  while  Haim 
(1904),  Cohn  (1904)  found  that  subluxation  occurred  in  flexion  of  the  forearm 
in  20-25%.  If^  these  cases  subluxation  was  always  associated  with  cubitus 
valgus,  without  evidence  of  any  previous  bony  injury.  Only  rarely  symptoms 
are  found  and  usually  insidious  in  their  onset.  When  signs  of  nerve  irritation 
are  present,    even   without    any  history   of  trauma,  and  with  an  apparently 


370       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

normal  bony  elbow,  the  nerve  should  be  transposed  as  has  been  recommended 
in  those  cases  when  the  nerve  similarly  suffers  as  a  result  of  fractures  of  the 
elbow. 

REFERENCES  * 

i\dson,  a.  \V.:  The  surgical  treatment  of  progressive  ulnar  paralysis,  Mayo  Clinic,  v.  lo: 

igiS,  p.  944. 
Bernhardt,   M.:  Beitragc  zur  Pathologic  der  Medianuslahmung,  Neurol.   Centralbl.,  v. 

16:  1897,  p.  626. 
Bonnet,  P.:    De    la  deviation  en  valgus  de  Pavant  bras  dans  les  paralj'sies  associees  du 

median  et  du  cubital,  Lyon  Chir.,  V.  16:  1919,  pp.  631-636. 
Brantjes,    M.:  Zur    Uberbriickung    von    Nervendefekten    bei   gleiclizeitiger   Ulnaris  und 

Medianus  Verletzung,  Deutsch.  Ztschr.  f.  Chir.,  v.  153 :   1920,  pp.  62-69. 
CoHN,  M.:    Uber  die   .^tiologie  der  Ulnarislahmungcn  nach  EUbogentraumen,  Centralbl. 

f.  Chir.,  V.  31:   1904,  p.  1400. 
COLLINET,  P.:  Luxation  congenilale  du  nerf  cubital.  Bull,  et  mem.  Soc.  anat.  de  Par.,  v. 

10:  5th  ser.  iSg6,  p.  358. 
Drouard,  H.:  Luxation  et  subluxation  du  nerf  cubital,  Paris,  1896,  Bailliere  et  Fils. 
Froment,  J.:  La  prehension  dans  les  paralysies  du  nerf  cubital  et  le  signe  du  pouce,  Presse 

med.,  V.  2^:  (Oct.  21,  1915),  p.  409. 
La  paralysie  de  I'adducteur  du  pouce  et  le  signe  de  la  prehension.  Rev.  Neurol.,  v.  22-2: 

1914-15,  p.  1236.     (Societe  de  Neurologic.  Oct.,  1915,  p.  1236.) 
Gierlich:  Ueber  tonischen  Kontrakturen  bei  Schussverletzungen  der  peripheren  Nerven, 

speciel  des   Ulnaris   und   Medianus,   Deutsch.  Ztschr.  f.  Nervenh.,  v.  63:  1918-1919,       1 

p.p.   145-160.  ; 

Grtjber,  W.:  Ueber  den  anomalen  \'erlauf  des  Nervus  ulnaris  vor  dem  Epitrochleus,  .Arch.       < 
f.  Anat.,  1867,  p.  560. 

Grund:    Ulnarislahmung  (Verein  d.  .Aerzte  in  Halle  a.  d.  S.  7  Feb.,  1917),  Munchen.  med. 
Wchnschr.,  1917,  34. 

Haim,  E.:  Uber  Luxation  des  LHnaris,  Deutsch.  Ztschr.  f.  Chir.,  v.  74:   1904,  p.  96. 

Henle,  J.:  Handbuch  der  .\natomie  des  Menschen,   Friedrich  Mcwig  und  Sohn,  Braun- 
schweig, III,  1876. 

Hermann-Johnson,  F.:  On  treatment  of  nerves  at  site  of  injury,  for  removal  of  fibrous 
tissue  and  reUef  of  pain.  Arch.,  Radiol.  &  Electroth.,  v.  23:  1918,  p.  66. 

Hunt,  J.  R.:  Paralysis,  J.  A.  M.  A.,  v.  66;  Jan.  i,  1916,  p.  11. 

Klauser,  R.:  \'erlagerung  des  Nervus  ulnaris,  Munchen.  med.  Wchnschr.,  v.  74:  1017, 

P-  635- 
Krause,  W.:  Traumatische  Angiectasie  des  linken  Armes,  Arch.  f.  klin.  Chir.,  v.  2:  1S61, 

p.  142. 
M.4.\s,   0.:  (Berhn)  Angeborener  linksseitiger  Ulnarerdefekt,  Berl.  klin.  Wchnschr.,  v.  74: 

1917,  P-  234. 
Mouchet:  Paralyse  tardive  du  nerf  cubital  a  la  suite  des  fractures  du  condyle  interne  de 
I'humerus,  J.  de  Chir.,  v.  12:   1914,  p.  437. 


ULNAR    NERVE  ,571 

I'KRLS:  Ein  neuer  Fingerpendelapparat,  Miinchcn.  mcd.  Wchnschr.,  1916,  Feldarzll.  Beil., 

Nr.  ,37. 
I'lTRES,  A.  et  ^Marciiand,  L.:  Etude  sur  les  grctTes  cubitales.  Rev.  Neurol.,  v.  35:  1919, 

PP-  370-398. 
PlETRI,   G.   .\.   and  Riquier,   G.   C:  Contributio  alia  determinazione   della   toi)ugraphia 

fasciculari  del  iiervos  cubitali  al  hraccio,  Chir.  d.  Organ!,  di.  niovmento,  v.  3:   1919, 

P-  P-  336. 
I'ort:  Eine  Ulnarisbandage,  Miinchen.  med.  Wchnschr.,  v.  73:   1916,  p.  1506. 
Ranschburg,    P:  Ueber  klinische    Unlcrsuchung,   operative   Biopsie   und   Heilerfolge   be, 

unfrischen    und    veralteten    Fallen    von   Schussverletzungen  der   peripheren  Xcrvcni 

Bruns'  Beitrage,  v.  loi:  1916,  p.  521. 
Schaller,  W.  F.:  Delayed  ulnar  palsy  following  elbow  injury,  California  State  J.  M.,  Aug. 

1920. 
.SiiKRKEN,  J.:  Chronic  neuritis  of  the  ulnar  nerve  due  to  deformity  in  the  region  of  the 

elbow  joint,  Edinburgh  M.  J.,  v.  23:   1908,  p.  500. 
Stopford,  J.  S.  B.:  The  results  of  secondary  suture  of  peripheral  nerves,  Brain,  v.  43:  pt. 

I,  1920,  p.  I. 
Stracker,   O.:  Zur   Dauerapparatbehandlung   von   Nervenverletzungen,    Munchen.   med. 

Wchnschr.,  v.  73:   1916,  p.  1738. 
Tur.ver:  Further  examples  of  variations  in  the  arrangement  of  the  nerves  of  the  human 

body,  Jour.  .\nat.,  v.  3:   1873-74,  p.  297. 


CHAPTER  XVI 
LUMBOSACRAL  PLEXUS 

Embryological  Development. — In  the  development  of  the  lower  extremity 
torsion  and  rotation  of  the  femur,  similar  to  that  described  for  the  humerus, 
takes  place;  however,  rotaton  is  in  the  opposite  direction  and  the  extent  of 
torsion  is  greater.  We  have  seen  that  in  the  upper  extremity  the  preaxial 
border  rotates  lateral  and  caudad,  so  that  the  ventral  surface  looks  forward 
and  the  dorsal  backward,  whereas  in  the  lower  extremity  the  femur  rotates 
so  that  its  preaxial  border  is  turned  medial  and  cephalad,  its  postaxial,  lateral 
and  caudad.  Thus  the  dorsal  or  extensor  musculature  comes  to  lie  ventral, 
and  the  ventral  or  flexor  musculature,  dorsal;  the  reverse  of  the  upper  extremity. 
Primitive  ventral  musculature  is  innervated  by  ventral  branches,  and  dorsal 
by  dorsal  branches  irrespective  of  the  direction  of  rotation  or  the  migration 
of  the  muscles.  From  an  embryological  standpoint  it  follows  then  that  the 
primitive  dorsal  musculature,  though  rotated  ventrally,  should  be  innervated 
by  the  dorsal  divisions  of  the  lumbosacral  plexus,  and  the  primitive  ventral 
musculature,  though  rotated  dorsally,  by  the  ventral  divisions.  This  dis- 
tribution of  the  lumbosacral  plexus  obtains. 

The  anterior  crural,  the  superior  gluteal,  the  inferior  gluteal  nerves  and 
the  peroneal  portion  of  the  sciatic  nerve  are  formed  by  the  dorsal  divisions  of 
the  lumbosacral  plexus  and  supply  the  primitive  dorsal  musculature.  The 
gluteal  muscles  being  axio-appendicular  do  not  participate  in  the  rotation, 
but  remain  in  the  dorsal  position.  Being  primitive  dorsal  muscles,  they  are 
supplied  by  nerves  from  the  dorsal  divisions,  like  the  other,  originally  dorsal 
which  have  rotated  ventrally,  namely,  the  quadriceps,  peroneii  and  the  exten- 
sors of  the  foot  and  toes.  This  primitive  dorsal  group  is  supplied  through  the 
gluteal,  anterior  crural  and  peroneal  nerves.  The  primitive  ventral  muscula- 
ture, though  rotated  medial  and  dorsal,  is  supplied  by  ventral  divisions  of  the 
lumbosacral  plexus  through  the  obturator  nerve,  the  nerve  to  the  hamstrings 
and  the  tibial  division  of  the  sciatic.  To  this  generalization  of  motor  inner- 
vation the  biceps  femoris  is  an  apparent  exception,  being  supplied  by  two  sets 
of  nerves,  one  from  the  ventral  and  the  other  from  the  dorsal  divisions.  How- 
ever, when  it  is  recalled  that  the  biceps  femoris  represents  a  fusion  of  muscula- 

372 


LUMBOSACRAL    PLEXUS 


373 


N.  glutaeus  inferior  " 

N.  tibialis' 
to  lum.  adductor  niagnus, 

semimembranosus, 
semitendinosus  nnd  cai»ut,-' 

longum  ni.  bicipitis  ,  ' 

to  mm.  quadralus  femoris'     ^' 

et  gemellus  inferior         / 
to  mm.  obturator  internus  ' 
et  gemellus  superior 
N.  eutaneus  femoris  posterior 

N.  clunium  inferior  niedialis 

Nn.  pcrinei  et  dorsalis  penis  (clitoridis) 


TL12 


Karaus  eutaneus  lateralis 

N.  iliohypogasiricus-- 

N,  genitotemoralis'  - 

Ramus  eutaneus  lateralis 
n.  iliohypogastrici 

N.  ilioiiiguinalis.  - 
10  mm.  psoas  major  et  minor--':. 

N.  spermaticus  extenuis-  ■ 

X.  eutaneus  femoris  lateralis -- 

N.  lumboinguiualis- - 

to  ra.  iliaois-  - 

N.  femoralis-{ 
to  mm.  psoas  major  et  iliacus- ' 
N.  obturatorius  accessorius  ' 
N.  obturatorius  - 
K.  glutaeus  superior' 


N.  peronaeus  ' 


to  ni.  iiiter- 
transveriariuH 
to  :u.  .(Uiidralus 
lumburum 


to  m.  intcr- 
transversarius 

to  m.  qiiadratus 
lumboi  um 


to  m.  inicr- 

transversarius 

to  111.  quadratus 

himborum 


lo  m.  inter- 

transversarius 

to  m.  quadratus 

himborum 


to  ni.  inter- 
transversarius 


10  m.  piriformis 


Ple.xus 
lumbalis 


Plexus 
Bacralis 


Plexus 
pudeudus 


Plexus 
coccygeus 


Nn.  haemorrhoidales  inferiores 

to  m.  levator  ani 


N:i.  ar.ococeygei 
to  m.  coccygeus 


Fig.   164. — Ki^iit  plexus  lumbosacralis,  schematic,  viewed  from  in  front  (after  P.  Eisler).     (The 
trunks  shaded  green  arc  derivatives  of  tlie  dorsal  half  of  the  plexus.) 


374      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERLPHERAL    NERVES 

ture  derived  from  both  ventral  and  dorsal  sources  this  dual  innervation  is 
readily  understood  and  serves  to  indicate  the  embryological  development  of 
this  muscle.  The  long  head  of  the  biceps  receives  a  ventral  branch,  from  the 
first,  second  and  third  sacral,  through  the  nerve  to  the  hamstrings,  and  the 
short  head  a  dorsal  branch  from  the  fifth  lumbar  and  first  and  second  sacral, 
through  the  peroneal  nerve.     (See  Fig.  164.) 

Variations  in  the  segemental  contribution  to  the  lower  extremity  are  more 
frequent  than  in  the  upper  extremity,  due  perhaps  to  the  fact  that  the  position 
of  the  limb  bud  for  the  lower  extremity  is  more  variable  than  the  upper  in  its 
relation  to  the  body  segments.  Harrison  (1907)  has  shown  that  the  presence 
of  the  limb  bud  determines  the  nerve  supply;  and  the  segmental  contribution 
varies  with  the  position  and  width  of  the  limb  bud.  Variations  in  the  posi- 
tion of  the  limb  bud  of  several  segments  more  cephalad  or  caudad  result  in 
variation  in  the  segmental  distribution  of  the  nerves  to  the  extremity.  Thus 
the  same  factors  apply  to  the  lower  as  to  the  upper  extremity.  The  most 
cephalic  position  of  the  cephalic  border  of  the  limb  bud  for  the  lower  extremity 
may  be  opposite  the  eleventh  thoracic,  while  its  most  caudad  position  may  be 
opposite  the  second  or  third  lumbar — thus  relatively  wide  variations  in  the 
segmental  components  may  exist.  In  about  one-fifth  of  the  cases  examined 
by  Eisler  (18Q2)  relatively  wide  variations  were  found,  though  in  the  majorityi 
the  lumbosacral  plexus  was  formed  from  the  more  caudal  segments;  hence 
more  often  the  postfixed  type  than  the  prefixed  type  of  plexus  is  met. 

In  the  prefixed  plexus  the  obturator  nerve  is  made  up  of  first,  second  and 
third  lumbar,  and  in  the  postfixed,  the  second,  third,  fourth  and  fifth  lumbar, 
while  the  anterior  crural  in  the  former  type,  is  made  of  twelfth  thoracic,  first; 
second,  third  and  fourth  lumbar,  and  in  the  postfixed  the  second,  third,  fourth 
and  fifth  lumbar.  Thus,  in  the  anterior  crural  of  the  prefixed  type  the  twelfth 
thoracic  contributes,  whereas  there  is  no  such  contribution  in  the  postfixed 
variety.  Similarly,  the  tibial  nerve  in  the  prefixed  plexus  type  is  made  up 
of  the  third,  fourth,  and  fifth  lumbar,  and  first  and  second  sacral;  while  in  the 
postfixed  the  third  and  fourth  lumbar  do  not  enter,  the  nerve  being  formed 
by  the  fifth  lumbar,  first,  second,  third  and  fourth  sacral;  thus  it  receives  a 
greater  sacral  contribution  than  in  the  prefixed  variety.  The  peroneal  nerve 
in  the  prefixed  is  formed  by  the  third,  fourth  and  fifth  lumbar,  and  first  sacral, 
and  in  the  postfixed  by  the  fifth  lumbar,  first,  second  and  third  sacral. 

The  importance,  clinically,  of  these  variations  in  the  formation  of  the  lum- 
bosacral plexus  is  comparatively  slight  and  is  only  referred  to  here  in  order  that 


LUMBOSACRAL   PLEXUS 


375 


certain  variations  in  the  motor  supply  of  the  lower  extremity  may  be  under- 
stood and  the  correspondence  in  variations  of  the  upper  and  lower  extremities 
better  appreciated. 

Injury  to  the  lumbosacral  plexus  is  comparatively  rare  due  to  the  fact 
that  necessarily  associated  with  any  lesion  of  the  plexus  are  concomitant  injuries 
which  in  themselves  are  frequently  fatal.  In  my  own  experience,  gunshot 
wounds  and  stab  wounds  in  this  region  have  not  called  for  neurosurgery.  Trau- 
matic rupture  of  the  plexus  is  difficult  of  accomplishment  without  other  exten- 


Sciatif 

Peroneal 

Tibial 

Anterior  Crura] 

Anterior  Tibial 

Lumbar  Plexvis 

Small  Sciatic 

Musculocutaneous 


Chart  XVII. — Table  to  show  relative  frequency  of  nerve  injuries  of  the  lower  extremity. 

sive  associated  injuries.  The  mechanical  factors  in  the  lower  extremity  differ 
materially  from  those  of  the  upper,  where  not  infrequently  rupture  of  the 
brachial  plexus  occurs  as  the  result  of  heavy  objects  falling  upon  the  shoulder 
or  forcible  separation  of  the  head  and  shoulder.  Such  injuries  are  not  possible 
in  the  lower  limb  because  of  its  alignment  with  the  body.  However,  one  case 
has  come  under  my  observation  of  bilateral  rupture  of  the  lumbosacral  plexus, 
during  violent  extraction  of  a  breech  presentation,  with  extensive  associated 
injuries  including  fracture  of  both  femurs.  The  diagnosis  of  bilateral  rup- 
ture of  the  lumbosacral  plexus  in  this  case  has  nevertheless  not  been  established 
beyond  criticism  in  my  mind,  due  to  the  extreme  difficulty  of  differentiating  it 
from  injury  to  the  lower  lumbosacral  cord.  A  satisfactory  and  detailed  sensory 
examination — impossible  in  an  infant — seems  to  me  to  be  essential  to  establish 
the  diagnosis.  Injuries  of  the  lumbosacral  plexus  have  been  reported  follow- 
ing forcible  closed  reduction  of  a  congenital  dislocation  of  the  hip. 

REFERENCES 
ElSi.ER,  p.:  Dcr  Plexus  lumbosacralis  des  Mcnsthcn,  Halle,  M.  Xiemeyer,  1892. 
Ferrier,  D.  and  Yeo,  G.  F.:  The  functional  relations  of  the  motor  roots  of  the  brachial 
and  lumbosacral  plexuses,  Proc.  Roy.  Soc.  of  London,  v.  32:  1881,  p.  12. 


376      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Gaskell,  W.  H.:  On  the  relation  between  the  structure,  function,  distribution  and  origin 
of  the  cranial  nerves  together  with  a  theory  of  the  origin  of  the  nervous  system  of 
vertebrata.  Jour,  of  Physiol.,  v.  10:  iSSg,  p.  153. 

Harrison,  R.  G.:  E.xperiments  in  transplanting  limbs  and  their  bearing  upon  the  problems 
of  the  development  of  the  nerves,  Jour.  E.xper.  Zool.,  v.  4:  1907,  239  ff. 

Jehring:  Das  peripherische  Nervensystem  der  Wirbelthiere  als  Grundlage  fur  die  Kenntniss 
der  Regionenbildung  der  Wirbelsaule,  Leipzig,  1878. 

Paterson,  a.  M.:  The  position  of  the  mammalian  limb  regarded  in  the  light  of  its  innerva- 
tion and  development,  Jour.  Anat.  &  Physiol.,  v.  ly.  1888-89,  p.  283;  also  in:  Brit. 
M.  J.,  v.  2:  1888,  p.  1207. 
The  origin  and  distribution  of  the  nerves  to  the  lower  limb,  Jour.  .\nat.  &  Physiol.,  v.  28: 
1893-94,  P-  84- 


CHAPTER  XVII 
THE  SCIATIC  NERVE  AND  ITS  DIVISIONS 

Anatomy.-  The  sciatic  nerve  is  made  up  of  ven- 
tral and  dorsal  divisions  of  the  fourth  and  fifth 
lumbar,  first,  second  and  third  sacral  roots  and  con- 
sists in  reality  of  two  nerves  in  one  sheath:  the 
tibial  from  ventral  divisions,  and  the  peroneal  from 
dorsal.  The  former  supplies  primitive  ventral  and 
the  latter  primitive  dorsal  musculature.  Bothnerves 
are  united  by  a  fibrous  sheath  into  a  sinf'le  nerve  trunk 
about  2  cm.  wide  and  '2  cm.  thick.  They  may 
remain  together  throughout  their  course  or  sepa- 
rate at  any  level.  Dix-ision  of  the  sciatic  nerve 
into  the  peroneal  and  tibial  nerves  takes  place  in 
about  20%  of  cases  high  in  the  thigh  (Eisler,  1892). 
If  the  separation  of  these  two  nerves  occurs  in  the 
pelvis,  they  leave  the  pelvis  separately,  the  peroneal 
above  or  through  the  pyriformis  muscle  and  the  tibial 
lu'low  it. 

The  nerve  to  the  inner  hamstring  muscles  arises 
separately  from  the  lumbosacral  plexus  in  more  than 
80%  of  the  cases,  and  in  the  remainder  it  is  incor- 
porated in  the  medial  border  of  the  sciatic  sheath. 
(See  Figs.  165,  166.)  In  the  lateral  border  of  this 
sheath  the  nerve  to  the  femoral  head  of  the  biceps 


Fig.  165. — Sciatic  nerve.  Surface  projection,  i,  Peroneal  di- 
vision; 2,  tibial  division;  3,  nerve  to  inner  hamstrings;  4,  upper  group 
of  branches  to  semitendinosus,  ischial  head  of  biceps;  5,  lower  group 
of  branches  to  semitendinosus,  semimembranosus  and  adductor 
magnus;  6,  nerve  to  short  head  of  biceps  (femora!  head) ;  7,  branches 
of  the  tibial  nerve  to  the  gastrocnemius;  8,  tibial  communica- 
ting; 8',  peroneal  communicating;  S",  external  or  short  saphenous; 
9,  branch  to  soleus  and  plantaris;  lo,  fjranch  to  deep  (Icxors  of 
the  calf  (tibialis  po.sticus,  flexor  digitorum  longus,  flexor  halhicis 
longus);  II,  branch  to  flexor  hallucis  longus. 

.577 


378      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


is  found.  Thus  at  the  lower  border  of  the  pyriformis  muscle  the  sciatic  nerve 
contains  really  four  nerves:  from  within  out  they  are,  the  nerve  to  the  ham- 
strings, the  tibial,  the  peroneal  and  the  nerve  to 
the  femoral  head  of  the  biceps. 

Cotirse  in  the  Thigh. — Thus  arranged  the  sciatic 
nerve  leaves  the  pelvis,  below  the  pyriformis 
muscle,  through  the  great  sacrosciatic  notch  and 
extends  into  the  thigh  as  far  as  the  popliteal  space, 
where  it  separates  into  its  component  divisions. 
In  its  course  the  nerve  lies  upon  the  external 
rotators  of  the  thigh  (gemellus  superior,  obturator 
internus,  gemellus  inferior  and  quadratus  femoris) 
and  on  the  dorsal  surface  of  the  adductor  magnus. 
The  nerve  is  covered  by  the  gluteus  maximus 
muscle  in  the  thigh  and  is  crossed  obliquely  from 
within  out  by  the  long  head  of  the  biceps.  In 
the  gluteal  region  the  nerve  lies  at  the  juncture 
of  the  inner  and  middle  thirds  of  a  line  connecting 
the  great  trochanter  and  the  tuberosity  of  the 
ischium.  The  most  superficial  parts  of  the  nerve 
are  at  the  lower  border  of  the  gluteus  maximus 
and  at  the  entrance  of  the  nerve  into  the  popliteal 
Fig.  i66.-.\erve  to  hamstrings,  space,  at  which  points  it  is  covered  only  by  skin 
Surface    projection.    3,    Nerve    to  and  fascia.     It  is   important  to  remember  that 

semimembranosus,      semitendinosus      ,,,,.,, 

and  long  head  of  biceps;  6,  nerve  to  ^he  fold  ot  the  buttock  does  not  reach  to  the  lower 

sliort  liead  of  biceps;  4,  upper  group  edge  of  the  gluteus  maximus  but  lies  approxi- 

of  branches  to  semimembranosus  and 

ischial  head  of  biceps;  s,lowergroup  mutely  4  to  6  cm.  above  it. 

of  branches  to  semitendinosus,  semi-       In  the  popliteal  space  the  tibial  division  lies 

membranosus  and  adductor  magnus.  -    .    ,  .  1  •        1         •  1 

This  figure  isshown  to  emphasize  the  superficial,  upon  the  popliteal  vem,  the  artery 

point  that  the  nerve  to  the  ham-  beneath  the  vein.     The  nerve  descends  vertically 
strings,  3,  is  a  separate  nerve  and  not  ,            ,       ,            .  ,  ,,         ■      1               i-        1                  1 
a  branch  of  the  sciatic.    The  nerve  through  the  middle  ot   the  popliteal  space,  be- 
to  the  short  head  of  the  biceps  may  tween  the   two  heads  of  the  gastrocnemius   to 
be  a  separate  nerve  and  in  anv  case  ,                 .        .       ,           ,                               _,, 
it  hes  as  a  separate  bundle  along  the  enter  the  opening  m  the  soleus  muscle.     The  pe- 

lateral  margin  of  the  peroneal  divi-  roneal  division  diverges  from  the  tibial,  crossing 

sion  of  the  sciatic  nerve.  ,        ,  ,  r      1  1    •  .1 

the   lateral   part   of   the   space,  lying  upon  the 

lateral  head  of  the  gastrocnemius,  immediately  beneath  and  along  the  medial 

margin    of    the    biceps    tendon.      The    peroneal    division    is    smaller    than 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  .579 

the  tibial  and  in  the  upper  ])art  of  the  space  lies  in  a  slis;htly  more  dorsal 
j)lane. 

Though  the  sciatic  nerve  is  flattened,  it  is  not  so  in  the  transverse  plane 
but  rather  obliquely,  the  peroneal  division  bein.g  lateral  and  dorsal,  and  the 
tibial  medial  and  ventral.  This  disposition  of  the  two  main  divisions  of  the 
nerve  trunk  may  be  due  to  the  rotation  which  the  lower  extremity  and  its 
muscles  undergo  in  development,  thus  entailing  with  their  rotation  a  corre- 
sjjonding  torsion  of  the  nerve  trunk. 

The  peroneal  and  tibial  nerves  though  incorporated  into  one  sheath  are 
distinct  both  functionally  and  anatomically,  the  former  supplying  the  primitive 
dorsal,  now  ventral  musculature,  and  the  latter  the  primitive  ventral,  now 
dorsal  musculature.  There  are  no  intercommunicating  libers  between  these 
two  nerves  throughout  their  entire  length,  yet  the  septum  between  the  divi- 
sions may  be  so  thin  that  a  line  of  demarcation  is  made  out  only  with  difficulty. 
'I"he  line  of  cleavage  between  the  two  nerves  lies  more  or  less  obliquely  so  that 
if  an  incision  is  carried  in  a  direct  ventral-dorsal  direction  either  the  peroneal  or 
tibial  nerve  may  be  injured  in  efforts  to  separate  them.  The  tibial  component 
is  generally  larger  than  the  peroneal  and  may  be  said  to  make  up  about  60  to 
7o'^'(,  of  the  total  fibers  of  the  sciatic  nerve.  Compton  (1917)  believes  that  this 
relationship  must  guide  one  in  separating  the  two  nerves  when  it  is  not  possible 
to  make  out  a  line  of  cleavage  between  them.  In  the  author's  experience  he 
has  not  seen  at  operation,  a  sciatic  in  which,  by  careful  palpation,  it  was  not 
possible  to  make  out  a  line  of  separation  between  the  two  divisions.  Fre- 
quently no  line  of  demarcation  is  seen,  but  by  rolling  the  nerve  between  the 
thmnb  and  index  linger  the  line  of  cleavage  may  be  felt. 

In  its  course  the  sciatic  nerve  is  accompanied  by  a  branch  of  the  inferior 
gluteal  artery,  the  arteria  comes  nervi  ischiatici,  which  runs  downward  on  the 
dorsal  surface  of  the  nerve,  generally  between  the  tibial  and  peroneal  divisions 
and  is  reinforced  by  branches  from  the  jjerforating  arteries  of  the  profunda 
fcmoris.  (See  Fig.  167.)  The  nerve  may  also  be  accompanied  by  several 
wins  or  by  one  single  large  vein.  These  veins  may  become  enlarged  and  vari- 
cosed  giving  rise  to  pressure  and  irritative  signs. 

Course  in  the  Leg. — The  tibial  di\ision  continues  in  the  leg  as  the  pos- 
terior tibial  nerve  entering  the  calf  bi'twcen  the  two  heads  of  the  gastrocnemius 
and  througli  the  tendinous  arch  of  the  soleus  muscle  together  with  the  posterior 
tibial  vein  and  artery.  It  maintains  its  position  superficial  and  dorsal  to  them. 
It  lies  in  a  sheath  of  the  intermuscular  sei)tum  between  the  deep  and  superficial 


380      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

muscles  of  the  calf  as  far  as  the  medial  malleolus,  below  which  it  enters  the  sole 
of  the  foot.  Thus  in  the  upper  part  of  the  leg  it  lies  ventral  to  the  soleus 
muscle  and  in  the  lower  part  ventral  and  medial  to  the  tendo  achilles. 

The  peroneal  nerve  winds  around  the  head  of  the  fibula  (see  Fig.  168), 
separated  from  the  dorsal  surface  of  the  head  of  the  hbula  by  the  tendinous 


Sciatic  artery 


A.  comes  nervi 
ischiatici 


Small  Sciatic  nerve 


Sciatic  nerve^ 


1st  perf.__ 


Profunda  artery  j 


' Sciatic  vein 


-Int.  eric. 


.Perfer. 


Perfer. 


Fig.  167. — Arteries  and  veins  of  tlie  sciatic  nerve  injected  in  an  infant.     (Poirier  and  Charpy.) 


origin  of  the  soleus,  and  from  the  external  surface  by  a  dense  layer  of  connective 
tissue.  The  nerve  is  most  superficial  in  this  region  being  covered  only  by  skin 
and  fascia.  Here  the  deep  fascia  of  the  leg  overlying  the  nerve  is  thickened  to 
form  a  dense  fascial  band  to  protect  the  nerve.  As  the  nerve  gains  the  front 
of  the  leg  it  passes  through  a  fibromuscular  canal  in  the  upper  part  of  the 
peronaeus  longus  muscle  and  then  breaks  up  into  its  terminal  branches. 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS 


381 


Fig.  168. — Peroneal  nerve.  Surface  projection.  1,  Peroneal  nerve;  2,  recurrent  tibial  to 
knee-joint,  tibiofibular  articulation  and  tibialis  anticus;  3,  anterior  tibial  nerve;  3',  branch  to  tibialis 
anticus,  extensor  hallucis  longus,  extensor  digitorum  longus  and  peronaeus  tertius;  4,  musculocu- 
taneous nerve  to  peronaeus  longus  and  peronaeus  brevis;  4',  internal  and  external  cutaneous  (terminal 
branches). 


382      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Branches  in  Thigh. — The  nerve  to  the  inner  hamstrings  inckiding  the 
ischial  head  of  the  biceps  has  been  commonly  considered  as  a  branch  of  the 
sciatic  nerve.  Its  relation  to  the  sciatic  trunk  has  already  been  pointed  out. 
Due  to  the  separation  of  this  nerve  from  the  nerve  trunk,  it  is  rare,  even  in  com- 
plete severance  of  the  sciatic  nerve  at  the  level  of  the  pyriformis  muscle,  to  find 
paralysis  of  all  of  the  hamstring  muscles.  The  fact  that  the  hamstrings  receive 
a  separate  nerve  supply  is  a  point  of  great  clinical  significance.  Failure  to 
appreciate  this  has  led  to  error  in  interpreting  sciatic  nerve  injuries.  Thus, 
ability  to  flex  the  leg  on  the  thigh  following  excision  of  a  tumor  from  the  sciatic 
nerve  below  the  gluteal  fold  was  interpreted  as  evidence  of  regeneration  by  Mack- 
enzie (1909),  whereas,  as  a  matter  of  fact,  the  nerve  supply  to  the  hamstrings, 
given  off  above,  had  at  no  time  been  severed.  This  nerve  to  the  ischial  head  of 
the  biceps,  semitendinosus,  semimembranosus  and  adductor  magnus  muscles  lies 
on  the  medial  border  of  the  sciatic  nerve,  and  is  made  up  of  ventral  divisions 
for  the  supply  of  these  primitive  ventral  muscles.  The  nerve  is  distributed  in 
two  groups  of  branches:  a  higher  group  which  sends  twigs  to  the  ischial  head  of 
the  biceps  and  to  the  semitendinosus,  at  their  origin  from  the  ischial  tuberosity, 
and  a  lower  which  reaches  the  semimembranosus  and  semitendinosus  about  the 
middle  of  the  thigh.  The  branch  to  the  semitendinosus  is  rather  long  and  sup- 
plies this  muscle  on  its  ventral  surface  in  the  interspace  between  it  and  tlie 
adductor  magnus.  The  branch  to  the  adductor  magnus  supplies  it  on  its 
dorsal  surface  at  several  points  in  the  middle  third  of  the  thigh.  (See  Figs. 
169,  170.) 

The  nerve  to  the  femoral  head  of  the  biceps  runs  as  a  separate  funiculus 
on  the  lateral  border  of  the  peroneal  division  of  the  sciatic  nerve  and  gradually 
turns  so  as  to  lie  on  the  ventral  surface.  It  is  made  up  of  the  dorsal  divisions 
of  the  plexus  and  leaves  the  main  nerve  stem  about  4  to  5  cm.  below  the 
ischial  tuberosity,  and  enters  this  head  of  the  biceps  on  its  dorsal  free  border. 
In  this  manner  it  runs  a  more  or  less  separate  course  of  12  to  15  cm. 

Branches  in  the  PopUteal  Space  and  in  the  Leg. — The  nerves  to  the  two 
heads  of  the  gastrocnemius  arise  from  the  tibial  division  near  the  apex  of  the 
popliteal  space  and  gradually  diverge  from  the  nerve  trunk  to  enter  the  medial 
and  lateral  heads  of  this  muscle.  (See  Fig.  171.)  Higher  up  the  two  branches 
unite  into  a  single  nerve  which  has  a  rather  long  intraneural  course  on  the 
dorsal  surface  of  the  nerve  trunk,  from  which  it  may  be  readily  dissected  up 
for  6  to  8  cm.  above  the  point  from  which  it  makes  its  emergence.  The  ner\-e  to 
the  soleus  may  arise  directly  from  the  tibial  division,  or  from  the  nerve  to  the 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS 


383 


N.  ischiadiais 
N.  obturatorius 
Spina  ischiadica 
MembraDa  obturatoria 
Bursa  in.  obturatoris  int. 

M.  quadratus  femoris 

Bursa  ischiadica  m.  glutaei 
maximi 

Bursa  ischiadica  subcut^ 


M.  adductor  inagnus  ■     h;  . 

1  '  ~ 


Tuberositas  glutaea 


M.  adductor  mioimus 


N.  pro.  m.  semi  mem  bran  050 


M.  adductor  niagnus   (portio  f 

muscularts) 


M.  adductor  magous  (portio         _ 
tendinea) 


M.  vastus  medialis 


Vasa  genu  superiora  medialia 


Trochanter  major 
M.  obturator  externus 
M.  iliopsoas 


V.  circumflexa  femoris 
mediaiis 


^     I    "-y       Hiatus  inferior  spurius  canalis  adductorii 

~*     ff—  Hiatus  inferior  venis  caualis  adductorii 
N.  tibialis 

K    peronaetv 


LpicondyUis  medialis 


Condylus  medialis 


Tondylus  lateralis 


I'ic.  169. — Nerve  distribution  to  the  adiluctor  magmis  aiul  adductor  brevis.     (Frohse  and  Frankle.) 


384      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


N,  peronaeus 


Origo  communis  (ni,  semitejidinosus  /  »| 

—  caput  longiim  m.  bicipitis)       x.       '  '1 

Aponeurosis  i  n  tcr  miiscularis  \    '        i^ 
J   I 


It* 

Septum  tcndineum  i  ntramusculare  /    I 

m.  semitendiDOsi 


Nerve  to  caput  breve 
m..bicipitis 


Origo  proprin 

semimembranosi 


1  M.  biceps,  caput 
longum 

2  M.  seraitnembraonsir 

3  M.  biceps,  caput 
breve 

4  M.  semitendioosus 


Fig.   170. — Nerve  distribution  to  the  flexor  group  in  the  thigh.     (Fruhse  and  Friinkel.) 


THE    SCIATIC   NERVE    AND    ITS    DIVISION  385 

gastrocnemius.  It  descends  vertically  upon  the  dorsal  surface  of  the  popliteus 
muscle  and  in  front  of  the  lateral  head  of  the  gastrocnemius  to  enter  the  soleus 
muscle  on  its  superficial  surface.  (See  Fig.  172.)  A  branch  to  the  plantaris 
muscle  is  also  given  off  at  this  level.  The  branch  to  the  popliteus  passes  over 
the  muscle,  winds  around  the  lower  border  and  supplies  it  on  its  deep  or  ventral 
surface.  It  also  gives  ofi  minute  muscular  branches  to  the  tibialis  posticus, 
vascular  branches  to  the  posterior  tibial  and  peroneal  arteries,  and  an  anterior 
interosseous  branch  which  supphes  the  anterior  tibial  artery.  Besides  these  it 
gives  off  an  articular  branch  for  the  knee-joint  and  the  tibial  communicating 
cutaneous  branch.  The  latter  unites  with  the  peroneal  communicating  to  form 
the  external  saphenous  nerve  which  is  distributed  to  the  skin  on  the  dorsum 
of  the  leg. 

In  the  leg  the  tibial  nerve  gives  off  muscular  branches  to  the  deep  fle.xors 
of  the  calf — the  tibialis  posticus,  flexor  hallucis  longus  and  flexor  digitorum 
longus.  (See  Fig.  173.)  The  branch  to  the  tibialis  posticus  arises  immedi- 
ately below  the  opening  in  the  soleus  and  enters  its  muscles  in  the  middle 
portion,  giving  off  also  a  branch  to  the  lower  half  of  the  soleus.  Thus  the 
soleus  muscle  receives  both  upper  and  lower  branches.  The  nerve  to  the 
flexor  hallucis  longus  may  arise  independently  or  with  the  nerve  to  the  tibialis 
posticus.  It  descends  with  the  peroneal  artery  and  supplies  the  flexor  hallucis 
longus  by  several  branches. 

Below  the  medial  malleolus  the  posterior  tibial  nerve  terminates  by  divid- 
ing into  the  internal  and  external  plantar  nerves.  The  former  is  the  larger  and 
supplies  the  muscles  along  the  inner  margin  of  the  foot,  namely,  the  abductor 
hallucis,  flexor  digitorum  bre\'is,  flexor  hallucis  brevis  and  the  first  lumbricale, 
while  the  external  ])lantar  supplies  all  the  remaining  muscles  of  the  sole  of  the 
foot.  The  internal  plantar  supplies  the  skin  of  the  inner  three  and  a  half 
toes,  the  external  planter  the  fifth  and  part  of  the  fourth  toe. 

In  the  popliteal  space  two  cutaneous  nerves  arise  from  the  peroneal  divi- 
sion, the  i^croncal  communicating  and  the  sural.  The  former  nerve  is  generally 
larger  than  Ihc  tibial  conmuinicating,  arises  from  the  peroneal  on  its  medial 
border  near  the  ajicx  of  the  pdjilileal  space  and  descends  vertically  across  the 
lateral  head  of  the  gastrocnemius.  It  has  a  long  intraneural  course  lying,  in 
the  thigh,  on  the  dorsal  surface  of  the  peroneal  division.  The  sural  nerve 
usually  arises  below  the  peroneal  communicating  but  may  arise  with  it.  It 
supplies  the  skin  of  the  upper  two-thirds  of  the  leg  on  its  lateral  surface. 

As  the  percincal   di\isi()n  passes   through   the  peron;eus  longus  nuiscle  it 


386         SURGICAL  AND   MECHANICAL  TREATMENT   OF  PERIPHERAL  NERVES 


\ 


i^ 


"1  iiiiin«ir "'*" 

Fig.  171. — Nerve  distribution  to  the  riglit  gastrocnemius  as  seen  on  t!te  deep  surface.     (Fruiise 

and  Frankel.) 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS 


387 


Corpuscul 
lamellosa  XJ^       / 


Caput  tibiale 


Raphe  mcdiana 

ct  R.  intcrmedius  W'  V 


j  ■  \   /     ■      I'J^"  Raphe  intramuscu- 

I      J/  1  y'  lai'is  lateralis 


R.  tcndincus  mcdialis 


R.  tcndineus  lateralis 


Fig.  172. — Nerve  distribution  to  the  soleus  niu^tlc  (left)  as  seen  on  the  deep  surface.     (Frohse 

and  Frankcl.) 


388       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


"M.  popliteus 


Origo  tibialis  m.  sole: 


R.  pro  m.  flexore  hallucis  longo 


^\  R.  pro  m.  tibialc  post. 


R.  pro  m,  Hexore  digitonim  Ion; 


M.  tibialis  posterior 


Sulcus  malleclaris 
medialis 


M.   flexor  dig.   Ion; 


^^_         Septum  intermusculareposl. 


Tendo  interosseus 


M.   flexor  hallucis  longus 


Arcus  teiidineus  inferior 


Sulcus  malleclaris  lateralis 


Fig.  I7S. — Xerve  distribution  to  the  deep  muscles  of  the  calf.     (Frohse  and  Frankel.) 


THE    SCIATIC    NKRVE    AND    ITS    DIVISIONS 


389 


X.  pfrrniiaeiis  rorinn. 
Tidctus  iliotihialii  — 


M.  biieps  fcmoris  (Cspitiiliitn 


HrAtus  peronaealis   profundus 


I""oraincii  nieml  r.  inter-- 
osstac  sup. 


Mcnibrana  interossea  cruris- 


X.  ppronaeus  superfic— — f— 


N.  prronaeus  profundus 


M.  peionaeus  brcvis— — 4- 


M.  fxt.  hall.  Ion 


M.  tibialis  ant« 


N.  pcroii.  prol.  - 


Foramen   incmbr.   intTos.-^rae  inf.  - 


Planum  iupiauialleolarc  (nobib) 


KfaMcvluii  lataali^  ' 


Fig.  174.— Xerve  distribution  to  tlie  extensor  group  and  ptTonaeus  brcvis.     (Frolise  and  Franltel.) 


390      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

breaks  up  into  its  terminal  branches — the  recurrent  tibial,  anterior  tibial  and 
musculocutaneous.     (See  Fig.  174.)     The  recurrent  tibial  arises  from  the  upper 


N.  peronaeus  communis 


Hiatus  peronaealis  communis 


N.  peronaeus  prof 


R.  musculaies  pro  m. 
peronaeo  longo 


Septum  intermusculare 
ant. 


M.  ext.  dig.  long, 


Hiatris  peronaealis  superficialis 
cum  nervo 


Tendo  m.  perouaei  longi 


M.  peronaeus  brcvis 


M.  peronaeus  tertius 


Malleolus  lateralis 


Fig.   175. — Nerve  distribution  to  the  peronaeus  longus,  extensor  digitorum  longus  and  peronaeus 

tertius.     (Frohse  and  Frankel.) 

border  of  the  peroneal  and  supplies   the  knee-joint   and  the   upper  part  of 
the  tibialis  anticus.     The  anterior  tibial  nerve  descends  between  the  tibialis 


ll 


THE    SCIATIC    NERVE    AND    ITS    DU'ISIONS  ,:59I 

anticus  and  extensor  digitorum  longus  and  extensor  hallucis  longus,  lying 
abo\'e,  lateral  to  the  anterior  tibial  vessels,  then  ventral,  and  below,  medial  to 
them.  The  nerve  is  mainly  muscular  for  the  tibialis  anticus,  extensor  digi- 
torum longus,  extensor  hallucis  longus  and  peronaeus  tertius.  (See  Fig.  175.) 
These  branches  are  given  off  near  the  origin  of  the  muscles  which  they  supply 
and  enter  them  immediately,  so  that  injury  of  the  nerve  in  the  middle  third 
of  the  leg  would  be  little  apt  to  interfere  with  its  main  muscular  distribution. 
The  anterior  tibial  also  gives  off  articular  branches  to  the  ankle-joint,  vascular 
l)ranchcs  to  the  anterior  tibial  vessels  and  cutaneous  branches  to  the  space 
ijetween  the  first  and  second  toes. 

The  musculocutaneous  nerve  supplies  the  peronaeus  longus  and  brevis  and 
the  skin  over  the  lateral  and  dorsal  aspect  of  the  leg  and  foot.  The  nerve 
arises  oblic(uely  from  the  lower  margin  of  the  peroneal  and  passes  vertically 
downward  in  a  sheath  of  the  intermuscular  septum,  which  separates  the 
peronaeus  longus  and  brevis  from  the  extensor  digitorum  longus. 

Funicular  Anatomy  of  the  Peroneal  Division. — The  peroneal  nerve  in  the 
thigh  has  an  upper  nerve  plexus,  corresponding  roughly  to  the  upper  third  of  the 
nerve,  consisting  of  numerous  nerve  bundles  with  rich  interlacing  of  nerve 
fibers.  This  plexus  is  followed  by  an  intermediate  zone  occupying  approxi- 
mately the  middle  third  in  which  the  funiculi  are  arranged  in  two  or  three  main 
bundles,  each  of  which  may  be  further  divided  into  smaller  bundles,  though 
rarely  completely.  Immediately  beneath  the  intermediate  zone  the  lower 
nerve  plexus  is  found.  This  plexus  begins  at  about  the  divergence  of  the 
peroneal  and  tibial  divisions  and  extends  downward  to  near  the  point  where  the 
peroneal  nerve  breaks  up  into  its  three  terminal  branches.     (See.  Fig.   176.) 

From  the  ujjper  plexus  three  nerves  arise:  the  peroneal  branch  to  the  fem- 
oral head  of  the  biceps — though  this  branch  may  exist  as  a  separate  nerve  even 
into  the  pelvis — the  sural  nerve  and  the  peroneal  communicating.  The  latter 
nerves  have  an  extremely  long  separate  intraneural  course,  being  formed  high  in 
in  the  thigh  and  sei)arating  from  the  peroneal  nerve  in  the  popliteal  space. 

The  relatixe  position  of  the  ner\-e  bundles  in  the  lower  third  of  the  peroneal 
nerve  \aries  with  the  le\el  examined.  Immediately  after  the  divergence  of  the 
peroneal  nerve  from  the  tibial  the  funiculi  are  arranged,  according  to  Compton 
(191 7),  in  three  groups:  the  peroneal  group  to  the  dorsal,  beneath  this  the  mus- 
culocutaneous, and  beneath  this  again  the  anterior  tibial.  Thus  at  this  level 
they  lie  in  a  strict  ventrodorsal  j)lane,  whereas  lower  down  the  relation  of  the 
bundles  is  altered,  so  that  they  lie  side  by  side  willi  the  most  ventral  group  now 


392       SURGICAL    AND     MECHANICAL    TREATMENT    OF    PERIPHERAL^ NERVES 

0 

1 

•J 


Fig.  176. — Origin  of  nerves  from  the  sciatic  plexuses  in  man.  The  plexus  is  only  drawn  at  the 
point  of  origin  of  the  nerves  and  irrespective  of  whether  it  is  in  the  anterior  or  posterior  surface. 
The  brackets  show  the  extent  of  U.P.,  upper  plexus;  /,  intermediate  region;  L.P.,  lower  plexus,  in 
the  respective  peroneal  and  tibial  divisions.  In  the  peroneal,  P  marks  a  stretch  of  the  upper  plexus 
in  which  the  plexus  was  less  than  above  and  below  it;  /  marks  a  stretch  in  which  the  characters  of 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  393 

most  mcfilal.  This  change  in  their  position  is  to  be  expected  in  view  of  the 
rotation  of  the  muscles  which  they  supply  from  a  dorsal  to  a  ventrolateral 
j)osition. 

In  a  comparative  study  of  the  peroneal  nerve  in  the  cat,  rabbit,  dog,  goat 
and  man,  Langley  and  Hashimoto  (1917)  found  a  close  correspondence  in  the 
anatomy  of  this  nerve.  In  all  these  mammals  an  upper  and  lower  nerve  plexus 
with  an  intermediate  region  was  found  with  the  lower  nerve  plexus  terminating 
in  three  main  nerve  bundles — a  common  group  for  the  peronaeus  longus,  brevis 
and  lerlius,  an  intermediate  grouji  for  the  cutaneous  fibers  of  the  musculo- 
cutaneous and  a  third  for  the  anterior  tibial,  to  the  tibialis  anticus,  extensor 
digitorum  longus  and  extensor  hallucis  longus.  The  nerve  to  the  peronaeus 
lerlius,  while  arising  from  the  musculocutaneous  nerve  in  man,  can  be  traced  in 
the  nerve  trunk  above,  into  the  funicular  bundles  which  form  the  common 
peroneal  group,  whereas,  in  the  cat,  Langley  and  Hashimoto  found  it  to  arise 
directly  as  a  peripheral  branch  from  the  nerve  to  the  peronaeus  longus  and 
brevis.  Occasionally  in  man  also  this  branch  may  be  given  off  from  the  nerve 
to  the  peronaeus  longus  ("MacAllister).' 

Funicular  Anatomy  of  the  Tibial  Division.—  The  tibial  ner\e  in  the  thigh, 
like  the  peroneal,  shows  an  upper  and  lower  plexus  with  an  intermediate  zone 
between  the  two,  though  the  latter  is  less  sharply  defined.  The  upper  plexus 
extends  well  into  the  pehis  and  seems  in  reality  to  be  almost  a  direct  con- 
tinuation of  the  fiber  distribution  which  takes  place  in  the  lumbosacral  plexus 
itself.  In  most  instances  there  are  no  branches  from  tliis  part  of  the  tibial 
division.  The  nerve  to  the  hamstrings,  appearing  to  arise  from  it,  is  in  reality  a 
distinct  and  separate  nerve.  As  has  already  been  pointed  out,  this  nerve  must 
l)e  considered  as  an  independent  nerve  and  not  a  branch  of  the  sciatic. 

The  intermediate  zone  consists  of  separate  bundle  groups  with  some  inter- 
mingling of  the  libers.     The  number  of  the  bundles  varies;  frequently  ten  to 

the  intermediate  region  were  less  developed  and  the  plexus  greater  than  below.  In  the  tibial,  P 
marks  a  portion  of  the  intermediate  region,  in  which  rather  more  than  a  third  of  the  nerve  had 
scarcely  any  ple.\us,  the  rest  had  a  moderately  developed  ple.xus.  The  upper  half  of  the  lower  plexus 
of  the  tibial  consisted  of  a  varying  number  of  bundle  groups  running  at  different  points  an  isolated 
course  for  2  .^  cm.  In  the  external  popUteal  the  beginning  of  the  plexus  formed  by  the  three 
bundle  groups  is  shown.  The  nerves,  the  bundles  Ai,  /)■>  and  some  bundles  connected  with  bt, 
arc  pulled  away  from  the  trunk;  //,  hamstring  nerves;  B,  nerve  for  femoral  head  of  biceps;  T.S.,  tibial 
saphenous;  P.S.,  peroneal  saphena;  P.C.,  lateral  cutaneous;  G,  nerve  to  gastrocnemius;  .1,  probably 
articular  branch.  b\a,  Bundle  arising  from  the  upper  plexus  and  running  a  long  separate  course, 
most  of  the  fibers  of  .1  came  from  it;  h«a,  long  sejiaratc  bundle  arising  from  the  intermediate 
region.     (J.  \.  Langley  and  M.  Hashimoto,  Journal  of  Physiology,  1917.) 

'Quoted  from  Langley  and  Hashimoto,  Jour,  of  Physiology,  1917. 


394      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

fourteen  may  be  found  depending  on  the  level  of  the  section.  This  region 
is  not  as  truly  an  intermediate  zone  as  in  the  peroneal,  some  rearrange- 
ment of  libers  taking  place,  practically  forming  small  plexuses.     The  bundles 


Fig.  177. — Section  through  the  middle  of  the  popHteal  space.  Same  limb  as  Fig.  178.  i,  Tibial 
trunk;  2,  popliteal  vessels;  3,  common  peroneal  trunk  showing  peroneal  cutaneous  bundle  (dark) 
dorso-raedial,  anterior  tibial,  ventral  and  musculocutaneous  bundle  between  the  two;  4,  tibial 
cutaneous  bundle;  5,  gastrocnemius;  6,  skin.     (Compton,  Journal  of  .\natomy,  1917.) 


Fig.  178. — Transverse  section  through  right  fetal  leg  at  level  of  upper  end  of  tibial  diaphysis. 
I,  Tibial  trunk;  2,  popliteal  vessels;  3,  biceps;  4,  gastrocnemius,  outer  head;  5,  nerve  to  outer  head  of 
gastrocnemius;  5,  nerve  to  inner  head;  6,  nerve  to  popliteus — between  this  and  the  nerve  to  the  outer 
head  of  the  gastrocnemius  is  seen  the  nerve  to  the  soleus;  7,  anterior  tibial  bundle  (deep  peroneal); 
8,  musculocutaneous  bundle  (superficial  peroneal) ;  9,  branch  to  the  peronaeus  longus;  peroneal 
cutaneous  bundle;  11,  tibial  cutaneous  bundle  (posterior  cutaneous  nerve  to  the  calf);  12,  skin. 
(Compton,  Journal  of  .Anatomy,  191 7.) 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  395 

arc  not  united  into  a  few  large  bundle  groups  as  in  the  peroneal.     (See  Figs. 

177.178-) 

There  is  a  rather  close  resemblance  between  the  funicular  anatomy  of  the 
peroneal  division  and  its  homologue,  the  musculospiral  nerve  of  the  upper 
extremity,  and  between  the  tibial  division  and  the  median  and  ulnar  nerves. 
In  both  the  peroneal  division  and  the  musculospiral  nerve  the  funiculi  are 
united  into  one  or  two  large  bundle  groups  in  the  middle  third  of  the  thigh  and 
arm,  while  in  the  corresponding  position  the  tibial,  median  and  ulnar  nerves  are 
made  up  of  numerous  small  funiculi. 

From  the  lower  plexus  which  extends  upward  in  the  nerve  trunk  about  lo 
cm.  above  the  middle  of  the  popliteal  space  two  nerves  arise,  the  tibial  communi- 
cating and  the  branches  to  the  gastrocnemius.  These  two  nerves  usually  fuse 
forming  a  single  bundle  which  joins  with  the  bundle  forming  the  nerve  to  the 
soleus.  The  latter  nerve  and  the  nerve  to  the  outer  head  of  the  gastrocnemius 
may  form  one  branch  and  the  nerve  to  the  inner  head  of  the  gastrocnemius  a 
separate  branch,  though  these  usually  unite  in  the  tibial  nerve  into  a  single 
bundle.  The  tibial  communicating,  like  the  peroneal  communicating,  has  a 
distinct  intraneural  course  though  very  much  shorter  than  the  latter,  since  it 
arises  from  the  lower  plexus  in  place  of  the  higher.  Emerging  from  the  lower 
]>h-xus  arc  the  branches  for  the  calf  muscles,  namely  the  tibialis  posticus, 
l^lantaris  and  popliteus.  The  posterior  tibial  nerve  in  the  calf  is  made  up  of  two 
main  bundles,  an  inner  and  an  outer  which,  at  the  medial  malleolus  form  the 
internal  and  the  external  plantar  nerves. 

Exposure  of  the  Sciatic  Nerve.  Position  of  the  Patient. — The  patient  is 
placed  on  his  belly  with  sand  bags  under  one  shoulder  and  hip.  The  lower  leg 
is  slightly  flexed  so  as  to  relax  the  hamstrings.  For  this  purpose  a  small  table 
which  can  be  raised  is  placed  at  the  foot  of  the  operating  table  and  the  foot  fixed 
lo  the  small  table  so  that  the  desired  position  may  be  maintained  without  the  aid 
of  an  assistant,  and  the  elevation  may  be  altered  to  suit  the  convenience  of  the 
operator.  The  patient  is  draped  so  that  the  limb  is  entirely  free  and  can  be 
moved  in  any  direction  without  deranging  the  sheets.  A  separate  sheet  should 
be  passed  beneath  the  lower  extremity,  as  well  as  over  it.  A  stocking  made  of 
stockinette  material  put  on  the  lower  part  of  the  leg  and  foot  will  be  found  very 
convenient  as  it  has  the  added  advantage  of  fitting  snugly,  thus  permitting 
observation  of  muscular  movements  when  electrical  stimulation  of  the  nerve  at 
operation  is  done.     Ordinary  stockinette  is  quite  satisfactory. 

Incision;  Exposure  of  the  Upper  Tliird.-Yov  exposure  of  the  sciatic  nerve, 


396       SURGICAL    AND     MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

in  its  upper  third,  the  incision  advocated  by  Konig  (1916),  Guleke  (1916)  and 
Iselin  (1917)  is  modilied  so  as  to  permit  the  surgeon  to  follow  the  nerve  into  the 
thigh  without  making  a  separate  skin  incision.  (See  Fig.  179.)  The  principle 
of  this  incision  is  to  cut  the  tendon  of  insertion  of  the  gluteus  maximus  muscle. 
The  muscle  is  then  reflected  medially  and  upward  together  with  the  vessels, 
thereby  avoiding  transverse  section  of  the  muscle  fibers  and  also  the  profuse 
bleeding  which  frequently  accompanies  the  old  direct  incision  over  the  course  of 


Fig.  179. — Skin  incision  for  exposure  of  the  upper  third  of  the  sciatic  nerve.     (Stookey,  J.  A.  M.  A.; 

1920.) 

the  nerve.  In  this  region  both  the  veins  and  arteries  so  near  their  origin  are  very 
large,  and  in  making  an  incision  across  the  muscle  these  vessels  are  repeatedly 
cut  the  same  branch  being  severed  time  and  again.  This  makes  the  operation 
with  the  old  incision  extremely  tedious  and  expensive  physiologically,  in  view  of 
the  blood  loss  and  the  fact  that  muscle  fibers  are  cut  transversely. 

The  new  incision  begins  approximately  at  the  dorsal  inferior  ihac  spine  and 
is  carried  obliquely  downward  and  out  to  a  point  about  three  finger's  breadth 
medial  to  the  great  trochanter,  thence  curving  downward  and  inward  over  the 
gluteal  fold  to  the  median  Hne  of  the  thigh  dorsally.  The  incision  is  more  or 
less  in  the  shape  of  a  question  mark.     The  lower  and  outer  angle  of  the  skin 


THE    SCAITIC    NERVE    AXD    ITS    DIVISIONS 


397 


incision  is  undermined  to  the  line  of  attachment  of  the  gluteus  maximus  and 
this  attachment  is  freely  exposed.  The  deep  incision  is  now  made  parallel  to 
the  libers  of  the  gluteus  maximus,  separating  them  in  the  direction  of  their 
course,  beginning  abo\'e  at  the  upper  angle  of  the  skin  wound  and  passing 


\nd.  N.rerUcled. 


Nio  ouler  nei^d. 
oc  bucep  5 . 

ii  Scta-Uc  N. 

JmkLL    5Ct2y.T.tcN. 


Fig.  i8o. — E.xposure  of  (lie  sciatic  nerve  witli  separate  suture  of  the  small  sciatic,  the  nerve  to 
the  hamstrings,  the  sciatic,  and  the  l)ranch  to  the  femoral  head  of  the  biceps.  The  gluteus  maximus 
muscle  has  been  cut  at  its  insertion  and  reflected  medially,  together  with  the  large  gluteal  vessels. 


directly  down  wan  I  to  the  tendon  of  insertion.  The  insertion  is  then  cut  approxi- 
mately 2  cm.  from  its  bony  attachment  and  the  whole  muscle  is  reflected  up- 
ward and  toward  the  median  line.  If  the  incision  has  been  correctly  placed,  the 
main  vessels  are  reflected  upward  on  the  muscle  and  little  bleeding  is  encoun- 


398      SURGICAL    AND    MECHANICAL    TREATMENT     OF    PERIPHERAL    XER\ES 

tered,  and  the  nerve  is  freely  exposed  from  the  lower  border  of  the  pyriformis  to 
its  entrance  into  the  thigh.  With  this  exposure  the  nerve  may  be  traced  any 
distance  farther  down  the  thigh  merely  by  a  direct  prolongation  downward  of 
this  incision.     (See  Fig.  i8o.) 

Exposure  of  the  Sciatic  Xerve  in  the  Thigh. — The  most  accessible  portions 
of  the  sciatic  nerve  are  just  below  the  gluteus  maximus  muscle  and  at  its  en- 
trance into  the  popliteal  space  for  it  is  covered  in  these  regions  only  by  skin  and 
fascia.  For  exposure  of  the  nerve  in  its  upper  portion,  the  incision  should 
begin  midway  between  the  tuberosity  of  the  ischium  and  the  great  trochanter 
over  the  gluteal  fold,  and  extend  directly  downward  into  the  thigh  the  required 
distance.  In  fatty  individuals,  a  large  amount  of  subcutaneous  fat  is  encoun- 
tered. The  lower  border  of  the  gluteus  maximus  muscle  must  be  freed  from  its 
deep  fascia  and  retracted  upward.  At  the  junction  of  the  middle  and  upper 
thirds  of  the  thigh  the  nerve  is  crossed  by  the  biceps  which  passes  obliquely 
from  within  outward,  hence  in  this  exposure  the  hamstrings  are  retracted 
medially  and  the  biceps  laterally,  but  if  the  lesion  be  slightly  higher  the  biceps 
is  retracted  medially  as  well.  The  semimembranosus  tendon  may  be  mistaken 
for  the  nerve,  since  both  lie  close  together.  The  nerve  is  surrounded  by  fatty 
tissue  in  which  will  be  found  the  perforating  branches  of  the  profunda  femoris 
artery  and  their  accompanying  veins.  Along  the  medial  border  of  the  nerve 
the  muscular  branches  to  the  hamstrings  will  be  met  and  along  the  lateral 
border  the  branches  to  the  short  head  of  the  biceps.  If  possible  these  are  identi- 
fied within  the  scar  by  the  electrode  in  order  to  avoid  injury  of  them,  or  an 
attempt  may  be  made  to  identify  them  by  dissecting  downward,  freeing  the 
branches  as  they  arise.  The  two  divisions  of  the  nerve  may  be  separated  by 
beginning  below  where  the  line  of  division  is  usually  more  distinct.  In  certain 
cases  no  line  of  separation  may  be  seen  but  can  be  felt.  The  plane  of  separation 
between  the  two  nerves  must  be  carried  obliquely  in  order  to  avoid  injury, 
especially  to  the  peroneal  division.  Separation  of  the  nerves  is  frequently 
called  for  since  it  often  happens  that  one  division  is  injured  without  interruption 
of  conductivity  of  the  other.  The  peroneal  is  more  frequently  involved  than  the 
tibial  and  by  separation  of  the  two  nerves  suture  of  one  may  be  accomplished 
while  only  liberation  of  the  other  may  be  necessary.  In  determining  the  con- 
ductivity of  the  two  nerves  the  electrode  will  be  of  immense  help.  If  loss  of 
nerve  substance  has  been  extensive  flexion  of  the  knee  and  extension  of  the 
thigh  will  generally  permit  end-to-end  union.  The  leg  can  be  held  flexed  by 
bandages  and  a  molded  plaster  splint,  though  some  prefer  a  metal  right  angle 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS 


399 


splint.     The  foot  should  be  supported  Ijy  a  Jones  metal  club  foot  splint,   or 
plaster  gutter  splint. 

Exposure  in  the  Po  pi  ileal  Space.  —By  prolongation  of  the  incision  used  for 
exposure  of  the  nerve  in  the  thigh  both  divisions  of  the  sciatic  nerve  may  be 
exposed  in  the  popliteal  space  where  they  lie  superficial  to  the  popliteal  artery 
and  vein.     (See   Figs.    i8i,    182. J     Separation  of   the  nerve  into  tibial  and 


Fig.  iSi. — E.xposure  (if  the  external  and  internal  popliteal  nerves. 


peroneal  divisions,  even  in  low  se]Xiration,  occurs  at  the  upper  part  of  the 
space.  The  tibitd  division  descends  through  the  middle  of  the  space  to  pass 
beneath  the  superficial  muscles  of  the  back  of  the  leg,  while  the  peroneal 
di\-ision  descends  oblirjuely,  crossing  the  outer  head  of  the  gastrocnemius 
muscle  and  passing  superficial  to  the  head  of  the  fibula. 

Both  nerves  are  covered  by  the  popliteal  fascia,  fat  and  the  lower  portions 


400       SURGICAL    AND    MECHANICAL    TREATMENT    OF     PERIPHERAL    NERVES 

of  the  hamstrings.  The  external  saphenous  vein  enters  the  popliteal  vein  at 
about  the  middle  of  the  space.  If  there  is  much  scar  the  external  saphenous 
vein  may  be  occluded,  and  it  had  best  be  ligated  before  it  dips  down  to  meet  the 
popliteal.     Within  the  popliteal  space  important  muscular  branches  are  given 


Fig.  182. — E.xposure  of  the  external  and  internal  popliteal  nerves.  Dissection  carried  one 
stage  farther  than  in  Fig.  181.  In  this  patient  a  two  stage  operation  was  done,  the  nerve  ends  being 
freed  and  sutured  together  without  refreshening.  The  nerves  were  then  gradually  stretched  by 
gradually  lowering  the  leg  and  a  second  stage  done.  At  the  second  operation  normal  nerve  ends 
could  not  be  obtained  due  to  extensive  hemorrhage  and  organized  scar  throughout  the  nerve  both 
centrally  and  distally. 

off,  from  the  lateral  and  medial  borders  of  the  tibial  nerve,  to  the  two  heads  of 
the  gastrocnemius  muscle.  (See  Fig.  184.)  These  branches  arise  from 
the  nerve  relatively  high  in  the  popliteal  space,  2  or  3  cm.  above  the  level 
of  the  condyles,  run  obliquely  and  enter  the  outer  and  inner  heads  of  the 
gastrocnemius  slightly  below  their  origin. 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS 


401 


The  other  branches  in  the  popliteal  space  are  those  to  the  plantaris  and  to 
the  soleus  muscles.  The  latter  nerve  arises  just  above  the  point  at  which  the 
nerve  enters  the  tendinous  arch  of  the  soleus  muscle  and  at  this  level  the  tibial 
nerve  also  gives  off  a  deep  branch  for  the  deep  flexors  of  the  calf. 


Fig.  183. — Exposure  of  the  e.xternal  and  internal  popliteal  nerves  with  suture  of  the  external  pop- 
liteal and  liberation  of  the  internal  popliteal. 

The  tibial  communicating  and  ])ernneal  communicating  nerves  arise  in  the 
middle  of  the  space  from  the  dorsal  and  superficial  aspect  of  the  tibial  and 
peroneal  divisions.  These  branches  ncerl  not  be  considered  for  suture  if  the 
scar  in  this  region  is  extensive  for  they  are  purely  sensory  and  their  supply  is 
largel}"  o\'erlapped  by  the  internal  saphenous  nerve  and  the  cutaneous  branch  of 
the  musculocutaneous  nerve,  but  they  should  ije  idi'ntilied  to  a\oid  using  them 
in  suture  with  niutor  nerx'cs. 


402 


SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERIPHERAL  NERVES 


Whenever  possible  the  exposure  should  begin  above  and  proceed  down- 
ward. The  branches  may  thus  be  identified  as  they  arise  and  injury  to  them 
better  avoided.  The  hamstrings  above  and  gastrocnemius  below  are  widely 
retracted,  care  being  taken  that  the  retractor  does  not  injure  the  nerve  branches 
to  the  latter  muscle  or  the  peroneal  nerve  as  it  crosses  the  outer  head  of  the 


Fig.  184. —  Exposure  of  the  tibial  nerve  in  the  lower  part  of  the  popliteal  space  and  upper  part  , 
of  the  calf.  The  tendinous  arch  of  the  soleus  has  not  been  cut.  Xote  the  long  e.x'traneural  course  of  | 
the  branches  in  this  region. 


gastrocnemius.  The  most  difficult  part  of  the  operation  is  freeing  the  nerve  on 
its  deep  surface  where  it  lies  upon  the  popliteal  vein.  This  structure  is  also  fre- 
quently involved  in  scar,  yet  with  its  lumen  retained  to  permit  sufficient  blood 
flow.  Its  walls  are  readily  torn  and  dissection  of  the  nerve  from  the  vein  must 
be  done  with  extreme  caution.  Because  of  involvement  of  the  vein  in  scar, 
attempts  to  remove  the  scar  bed  are  often  impossible  and  here  Huber's  modified 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  403 

cargile  membrane  may  be  used  to  advantage,  not  to  surround  the  nerve  nec- 
essarily, but  merely  as  a  sheet  between  the  vein  and  the  nerve. 

If  the  motor  branches  to  the  gastrocnemius  are  destroyed  at  their  origin 
they  should  be  sutured  into  the  nerve  trunk  at  a  lower  level,  or  if  injured  as  they 
enter  the  muscle,  they  may  be  directly  implanted  into  the  muscle  at  a  slightly 
higher  level. 

Exposure  of  the  Tibial  Nerve.  The  tibial  nerve  in  the  upper  part  of  the 
leg  may  be  exposed  by  continuing  the  line  of  excision  used  to  expose  the  popliteal 
structures.  (See  Fig.  184.)  The  nerve  passes  through  a  tendinous  arch  in  the 
soleus  muscle  along  with  the  tibial  vessels  and  lies  between  the  deep  and  superfi- 
cial muscles  of  the  calf  in  a  sheath  of  the  intermuscular  septum  which  separates 
these  two  muscle  groups.  The  gastrocnemius  muscle  is  widely  retracted  and 
the  line  of  union  of  the  outer  and  inner  heads  is  split  and  the  fibers  of  the  soleus 
are  separated  as  far  as  possible.  The  tendinous  sheath  on  the  superficial  aspect 
of  the  soleus  may  be  mistaken  for  the  fascial  plane  between  the  deep  and 
superficial  muscle  layers. 

If  the  tibial  nerv'e  is  to  be  exposed  in  the  middle  or  lower  third  of  the  calf, 
an  easier  approach  than  through  the  soleus  is  gained  through  an  incision  made 
along  the  medial  border  of  the  calf  about  3  cm.  from  the  tibial  margin. 
The  deep  fascia,  recognized  by  its  transverse  fibers,  is  cut,  and  the  fascial  plane 
between  the  superficial  and  deep  muscles  is  then  sought.  The  tibial  nerve  will 
be  found  lateral  to  the  artery.  The  lower  the  nerve  is  sought  the  easier  becomes 
the  exposure  and  the  more  readily  is  it  brought  into  view.  In  the  upper  part  of 
the  calf  the  nerve  lies  upon  the  tibial  artery,  while  in  the  middle  third  thcnerve 
lies  between  the  tibial  and  the  peroneal  arteries.  The  latter  vessel  lies  adjacent 
to  the  motor  branch  for  the  flexor  hallucis  longus. 

Internal  and  External  Plantar  Nerves. — These  nerves  may  be  exposed 
behind  the  medial  malleolus  by  a  curved  incision  10  cm.  long  parallel  to  the 
dorsal  border  of  the  malleolus.  The  internal  arcuate  ligament  is  exposed  and 
divided.  Immediately  beneath  the  malleolus  will  be  found  the  sheath  for  the 
tibialis  posticus  tendon  and  adjacent  to  it  the  sheath  for  the  flexor  digitorum 
longus.  In  a  larger  space  below  this  tendon  the  plantar  nerves  and  vessels  are 
found,  and  below  them  a  space  for  the  flexor  hallucis  longus  tendon.  The 
nerves  enter  the  sole  of  the  foot  lying  on  the  deep  surface  of  the  abductor 
hallucis.  The  internal  [)lantar  nerve  passes  medial  to  the  flexor  digitorum 
longus  and  the  flexor  hallucis  longus — in  the  space  between  the  flexor  digitorum 
brevis  and  ahduilur  hallucis.     The  external  jilantar  passes  beneath  the  flexor 


404      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

digitorum  brevis  and  quadratus  planta\  The  external  and  internal  plantar 
nerves  in  the  foot  correspond  in  their  manner  of  distribution  respectively 
to  the  ulnar  and  median  nerves  in  the  hand. 


Fig.  185. — Exposure  of  the  peroneal  nerve  in  the  pophteal  space.  The  nerve  has  been  separated 
into  its  two  divisions — anterior  tibial  and  musculocutaneous — and  each  sutured  separately.  Note  the 
small  artery  between  the  two  divisions  below  the  suture.  Insert  shows  the  funicular  arrangement  of 
the  peroneal  nerve  at  the  level  of  the  suture. 

Exposure  of  the  Peroneal  Nerve.  Position. — The  patient  is  placed  in  a 
semiprone  position  and  the  leg  is  slightly  fie.xed.  The  entire  limb  is  then  held 
by  sand  bags  in  internal  rotation  so  as  to  expose  a  part  of  the  dorsal  surface  of 
the  popliteal  space.  The  sheets  are  placed  so  as  to  enable  the  position  of  the 
limb  to  be  altered  at  will  without  disturbing  the  field. 

Incision. — The  incision  is  made  obliquely  from  above  the  middle  of  the 
popliteal  space  along  the  medial  border  of  the  biceps  tendon  and  across  the 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  405 

fibula  about  an  inch  below  its  head.  The  jjopliteal  fascia  is  exposed  and  incised 
in  the  same  line  as  the  skin  incision.  The  nerve  is  then  sought  beneath  the 
border  of  the  biceps  tendon  and  followed  downward  across  the  fibula.  (See 
Fig.  185.)  As  the  nerve  crosses  the  fibula  it  is  somewhat  flattened  and  is  covered 
by  a  dense  connective  tissue  layer  which  is  a  lateral  expansion  of  the  biceps 
tendon  with  a  thickening  of  the  deep  fascia.  Two  main  bundle  groups  in  the 
peroneal  nerve  may  be  distinguished  in  the  popliteal  space,  one  lying  adjacent 
to  the  biceps  tendon  and  the  other  more  lateral  and  dorsal:  the  former  forms 
the  anterior  tibial  nerve  and  the  latter  the  musculocutaneous.  On  cross 
section  of  the  nerve  in  this  region  the  dorsal  bundle  consists  of  three  funiculi 
while  the  ventral  bundle  is  made  up  of  one  and  sometimes  two  funiculi.  Be- 
tween these  two  bundle  groups  of  the  peroneal  nerve  a  small  artery  and  \ein 
are  sometimes  found. 

Separate  suture  of  these  two  bundles  must  be  done  if  the  nerve  injury  is  at 
the  level  of  the  head  of  the  fibula.  When  end-to-end  union  cannot  be  accom- 
plished, due  either  to  wide  separation  of  the  nerve  ends  or  extensive  callus  from 
the  fibula,  nerve  graft  may  be  done  and  an  attempt  made  to  unite  each  graft 
with  the  same  bundle  centrally  and  distally. 

If  callus  is  extensive  the  surgeon  may  consider  excision  of  part  of  the  fibula 
but  leaving  the  attachment  of  the  biceps  to  the  head  of  the  fibula.  In  this 
manner  i  to  2  cm.  may  be  gained  and  a  better  nerve  bed  made.  Or  with 
an  exposure  similar  to  that  used  for  the  tibial  nerve  the  distal  end  of  the  nerve 
may  be  transplanted  through  the  soleus  muscle  and  a  nerve  graft  done.  To 
transpose,  an  incision  is  made  along  the  lateral  border  of  the  fibula  through 
the  deep  fascia  which  separates  the  soleus  muscle  and  the  peronaeus  longus. 
About  5  cm.  below  the  head  of  the  fibula  a  small  artery  will  be  seen  passing 
from  under  the  soleus  and  crossing  dorsally  onto  the  gastrocnemius.  (See  Fig. 
186.)  If  the  fibers  of  origin  of  the  soleus  are  exposed  here  a  small  split  in  the 
fibers  will  be  found — a  small  tendinous  arch  through  which  this  artery  passes. 
This  cleft  in  the  soleus  fibers  forms  a  natural  space  through  which  the  peroneal 
nerve  may  be  passed  into  the  back  of  the  calf  to  the  same  fascial  plane  in  which 
the  tibial  nerve  and  vessels  lie.  In  this  manner  a  sjjlendid  bed  is  formed  for  the 
nerve  and,  because  the  space  through  which  it  passes  is  a  natural  arch,  compres- 
sion of  the  nerve  is  not  likely.  In  freeing  the  distal  end  of  the  nerve  the  per- 
onaeus longus  muscle  is  cut  at  the  point  at  which  the  peroneal  nerve  passes 
under  it  and  the  unimportant  recurrent  tibial  branch  must  be  sacrificed.  After 
the  nerve  has  been  freed  sufficiently  to  ])erinit  lransj)osilion  without  angulation, 


4o6       SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

the  cut  ends  of  the  peronaeus  longus  are  sutured.  So  far  as  I  am  aware  this 
method  of  transposition  of  the  peroneal  nerve  has  not  generally  been  done. 
When  the  deep  scar  and  callus  are  extensive  and  the  overlying  scar  in  the  skin 
cannot  be  excised  nerve  suture  has  been  considered  impossible  and  nerve  graft 


Fig.  i86. — E.xtensive  injury  of  the  left  peroneal  nerve  as  it  winds  around  the  fibula,  with  marked 
callus  and  scar  formation  making  it  impossible  to  obtain  a  suitable  bed  for  end-to-end  suture  or 
nerve  graft.  The  upper  branches  of  the  anterior  tibial  and  musculocutaneous  nerves  are  sacrificed 
and  the  nerves  are  passed  through  the  well-marked  tendinous  arch  in  the  muscular  attachment  of  the 
soleus  which  prevents  pressure  being  made  on  the  nerves.  These  are  carried  through  to  the  dorsum 
where  end-to-end  suture  or  graft  may  be  done. 

impracticable.     It  is  particularly  in  these  cases  that  transposition  of  the  nerve 
through  the  soleus  muscle  should  be  attempted. 

Deformity. — As  has  been  pointed  out  above,  even  in  complete  anatomical 
interruption  of  the  sciatic  nerve  as  high  as  the  sciatic  notch  total  paralysis 
of  all  muscles  of  the  thigh  rarely  occurs,  since  the  motor  branches  to  the  long 
head  of  the  biceps  and  to  the  semitendinosus  are  not  branches  of  the  sciatic 
nerve  but  separate  nerves  which  enter  these  muscles  close  to  their  origin  as 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  407 

well  as  lower.  Hence  these  two  muscles  are  rarely  involved  in  paralysis  of 
the  sciatic.  The  semitendinosus  escapes  more  often  than  the  long  head  of 
the  biceps  and  it  alone  is  capable  of  performing,  to  a  remarkable  degree,  the 
function  of  the  other  hamstrings  as  well  as  the  slight  flexion  action  of  the  leg  on 
the  thigh  contributed  by  the  gastrocnemius  muscle.  Even  in  total  paralysis  of 
all  the  flexors,  with  the  exception  of  one  head  of  the  biceps  or  the  semitendino- 
sus, relatively  little  impairment  of  function  is  shown  when  a  suitable  apparatus 
is  worn.  One  patient  having  a  combined  sciatic  and  anterior  crural  paralysis 
was  able  to  walk  without  much  inconvenience,  whentitted  with  proper  mechan- 
ical support,  due  to  the  action  of  the  semitendinosus  and  the  compensatory 
action  of  the  flexors  and  extensors  of  the  thigh  on  the  trunk. 

The  contour  of  the  dorsal  surface  of  the  thigh  is  symmetrically  flattened 
and  tapered,  but  if  the  innervation  of  the  semitendinosus  is  retained  this  muscle 
may  be  distinctly  seen  as  a  raised  band  on  the  inner  part  of  the  thigh. 

In  paralysis  involving  both  the  tibial  and  peroneal  divisions,  innervation 
of  all  the  muscles  below  the  knee  is  lost.  The  foot  hangs  flaccid,  dangling 
in  the  ])osition  of  complete  foot-drop.  Either  Aarus  or  valgus  deformity 
together  with  flatfoot  are  also  found.  On  account  of  the  loss  of  all  sensation  the 
I)ainful  symptoms  of  flatfoot  are  not  present  and  it  may  not  be  recognized  until 
after  regeneration  has  taken  place. 

Mechanical  Treatment. — The  aim  of  proper  mechanical  treatment  is 
to  give  stability  to  the  lower  leg  and  foot,  to  correct  postural  deformity  and 
faulty  deviation  of  body  weight  and  to  give  support  to  the  relaxed  arches  of 
the  foot.  Unless  all  these  factors  are  taken  into  consideration,  the  mechanical 
treatment  will  be  only  partially  of  value. 

Probably  one  of  the  most  satisfactory  appliances,  where  all  the  flexors 
of  the  thigh  are  paralyzed,  is  a  modified  Thomas  caliper,  permitting  flexion 
of  45°  at  the  knee.  (See  Fig.  194.)  This  apparatus  is  light,  comfortable  and 
extremely  serviceable.  There  are  many  splints  more  complicated,  but  none 
more  efficient.  In  place  of  a  stop  lock,  a  spring  lock  may  be  used,  so  that  the 
])atient  walks  stiff-legged  and  on  sitting  is  able  to  release  the  lock  and  bend 
the  knee.  The  caliper  is  fixed  to  a  plate  in  the  sole  of  the  shoe  which  extends 
from  the  heel  to  the  metatarsophalangeal  joints.  The  upright  is  so  fixed  to 
the  sole  plate  that  it  maintains  the  foot  slightly  dorsiflexed,  thus  preventing 
toe-drop  and  calcaneous  deformity.  .\  reinforcement  should  be  sewed  on  the 
inside  of  the  shoe,  and  the  sole  and  heel  raised  a  third  of  an  inch  on  the 
inner  border  to  i)re\'ent   \-algus  deformity  and  oft'er  additional  su])port  to  the 


4o8      SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


~ 


weakened  arches  of  the  foot  by  deviating  the  body  weight  to  the  outer,  stronger 
arch. 

In  sciatic  paralysis,  involving  both  tibial  and  peroneal  divisions  with 
retained  flexion  of  the  knee,  a  splint,  similar  to  the  one  in  Fig.  187,  will  be 
found  extremely  serviceable.  An  outside  fixed  iron  with  a  stop  lock  to  prevent 
valgus  deformity  and  extreme  plantar  flexion,  together  with  a  spring  arrange- 
ment to  overcome  toe  drop  and  assist  in  elevation  of  the  foot,  makes  a  very 
light  and  efficient  appliance. 

Deformity  in  Peroneal  Nerve  Injuries.-  The  ventral  and  lateral  muscle 
groups  of   the  leg  are  paralyzed  with  inability  to  dorsiflex  or  evert  the  foot. 

There  is  complete  toe-drop  and  tendency  to  varus 

deformity,  and,  in  neglected  cases,  equino-varus  oc- 
curs. Dorsal  elevation  of  the  os  calcis  is  marked, 
due  to  the  unopposed  action  of  the  muscles  of  the 
calf,  which  are  normally  about  five  times  more 
powerful  than  the  extensor  group.  In  untreated 
cases  with  marked  contracture  of  the  tendo-achilles 
subluxations  may  be  present.  Flatfoot  may  some- 
times occur  due  to  loss  of  support  to  the  arches  of 
the  peronei  and  the  extensor  groups,  the  former 
supporting  both  the  transverse  and  longitudinal 

„        „       r.  .  ■,     ■       ^..  J  arches,  and  the  latter  the  inner.     The  gait  is  very 
Fig.   187. — Outside   iron  btted  '  _  .  . 

with  rubber  device  to  replace  ex-  awkward   due  to  increased  flexion  at  the  knee  in 

tension  in  parab'sis  of  both  tibial  ^^^^^^  ^^   ^\^.^^  jj^e   tO^S  j^Oj^   the  floor,  and  partic- 

and  peroneal  nerves.     Stop  lock 

and  sole  plate  prevent  plantar  ularly  noticeable  in  walking  up  hill  or  upstairs,  or 

flexion.      (Stookey,    Surg.,    Gyn.  jj-,  ^y;,]l^in<r  fast. 

andObst.,  1918.)  '"" 

Mechanical  Treatment  in  Peroneal  Nerve  In- 
juries.— In  treating  this  parah'sis  it  is  obvious  that  more  should  be  done 
than  simply  to  correct  the  ^toe-drop  though  this  alone  is  of  great  help.  An 
outside  leather  support  should  be  sewed  to  the  shoe  to  give  support  to  the 
ankle  and  the  shoe  elevated  on  the  outer  border  both  of  the  sole  and  heel, 
thereby  deviating  the  body  weight  to  the  inside  of  the  foot,  thus  tending  to 
correct  the  varus  position.  Flatfoot,  if  present,  should  be  supported  by  an 
inside  plate,  such  as  described  in  paralysis  of  the  tibial  division. 

Most  appliances  used  in  this  paralysis  attempt  to  correct  but  one  of  the 
deformities,  namely  the  toe-drop,  and  ignore  others  of  almost  equal  importance. 
The  spring  shoulder  strap  of  ]\Iarie  and  Meige  corrects,  rather  awkwardly, 


THE    SCIATIC    NERVE    AND    ITS    DrV'ISIONS  409 

nothing  more  than  the  toe-drop  and  does  not  assist  in  the  correction  of  the  asso- 
ciated deformities.  To  obtain  elevation  of  the  foot  by  a  strap  running  across 
the  opposite  shoulder  seems  rather  farfetched.  The  metal  spring  device  of 
Leri,  which  passes  up  the  front  of  the  shoe  likewise  corrects  but  one  deformity. 
The  more  satisfactory  appliance  of  Robin-Chiray  (1916)  (Fig.  188),  having  a 
spring  effect  obtained  by  bending  spring  steel 
wire,  is  a  \'ery  convenient  and  useful  appliance, 
being  light  and  inconspicuous  and  yet  assisting 
admirably  in  elevation  of  the  foot,  though  it 
also  corrects  only  the  toe-drop.  A  similar  appli- 
ance has  been  advocated  by  Buerki  (1920).  (See 
Figs.  189,  190.)  When  a  spring  wire  appliance  is 
used,  as  well  as  in  the  other  appliances,  the  sole  and 
heel  of  the  shoe  should  be  raised  j^  inch  on  the 
inside. 

The  spring  appliance  with  inside  iron  illus-       „        „„     -r.    ■         c    t^  ^■ 
'        "      ^^  Fig.  188. — Device     of     Robm- 

trated  (see  Fig.  191)  not  only  mechanically  corrects  Chiray  for  foot-drop.  (Tinel,  "Les 
the  associated  deformities,  but  also  tends  to  replace  ^lessuores  des  Nerfs,"  1916.) 
the  action  of  the  extensors.     An  inside  iron  may 

be  used,  with  a  stop  lock  placed  to  prevent  plantar  fle.xion  and  the  iron  fixed 
to  hold  the  foot  slightly  dorsiflexed.  Either  a  metal  spring  or  a  rubber  band 
is  attached  to  the  shoe  at  or  just  beyond  the  metatarsophalangeal  Joint  and  to 
the  upright  inside  iron  above  the  middle  of  the  astragalotibiotibular  articulation, 
thus  giving  to  the  spring  or  rubber  band  an  adequate  ventrodorsal  pull.  Any 
slight  tendency  toward  inversion  in  the  pull  is  prevented  by  means  of  the  tixed 
iron,  the  outside  strap  and  the  elevation  of  the  shoe.  About  as  useful  is  an  in- 
side iron  without  a  stop  lock,  the  iron  being  rounded  at  the  end  and  made  to  lit 
into  a  socket  in  the  heel  of  the  shoe,  with  a  rubber  band  or  spring  to  prevent 
foot-drop.  However,  of  these  two  appliances,  the  former  with  the  stop  lock  is 
to  be  preferred. 

Deformity  in  Tibial  Nerve  Injuries.-  In  injuries  of  the  tibial  nerve,  paraly- 
sis of  the  muscles  of  the  calf  and  sole  of  the  foot  is  found,  with  loss  of  flexion  of 
the  toes,  abduction  and  adduction  as  well  as  plantar  flexion  of  the  foot.  The 
gait  is  without  spring,  the  step  heavy  and  inelastic,  the  weight  falling  entirely 
upon  the  heel.  Due  to  the  unopposed  pull  of  the  dorsal  flexors,  the  dorsal 
surface  of  the  os  calcis  tends  to  look  downward  in  place  of  backward.  The  arch 
appears  slightly  more  concave,  depending  upon  the  extent  of  the  contraction  of 


410       SURGICAL    AND    MECHANICAL    TREATMENT     OF     PERIPHERAL    NERVES 

the  tibialis  anticus  and  the  extensor  group  and  also  because  of  the  atrophy  of  the 
intrinsic  muscles  of  the  foot.  Valgus  deformity  is  usually  due  to  the  unopposed 
action  of  the  peronei. 


Fig.  i8g. — Splint  for  foot-drop  made  of  No.  ii  spring  steel  wire  and  held  to  the  shoe  with  four 
pieces  of  piano  wire.  The  splint  is  held  to  the  leg  by  a  canvas  band  passing  around  the  calf  between 
the  two  wires.     (Buerki,  Archives  of  Neurology  and  Psychiatry,  1Q21.) 


Omi 


0/A6  *  2. 


0/46.*  3 


OlA&.^  4  . 


Fig.   iqo. — Details  of  splint  for  foot-drop.      (Buerki,  .Archives  of  Neurology  and  Psychiatry,  1921.) 

Mechanical  Treatment  of  Tibial  Nerve  Injuries. — Proper  mechanical 
support  should  attempt  to  prevent  extreme  dorsiflexion,  calcaneous  deformity 
and  the  tendency  to  valgus  posture.     In  addition,  support  must  be  given  to  the 


THE    SCIATIC    NERVE    AND    ITS    DR-ISIOXS 


411 


{)lantar  arches.     An  outside  iron  with  stop  lock  to  prevent  dorsiflexion  beyond  a 
h'ttie  more  than  right  angle  will  correct  dorsiflexion  and  calcaneous  deformity. 


cz:p 


A.  B. 

Fig.  191. — Spring  device  giving  passive  extension  in  foot-drop.  .-1,  An  inside  iron  witli  fixed 
sole  plate  and  stop  lock  is  fitted  with  metal  spring  or  rubber  band  extending  from  above  center  of 
astragalotibiofibular  articulation  to  beyond  metatarsophalangeal  joint.  The  dorsal  pull  of  the 
spring  is  substituted  for  the  action  of  the  extensors.  The  inside  iron  and  ankle  strap  and  the  eleva- 
tion of  shoe  correct  the  associated  deformities;  B,  the  same  without  stop  lock  or  sole  plate.  Inside 
iron  fits  loosely  into  socket  in  the  heel  and  is  fitted  with  spring  device  similar  to  that  in'.I.  (Stookey, 
Surg.,  Gyn.  and  Obst.,  1918.) 


Fig.  192. — Short  caliper  for  paralysis  of  tibial  division  of  sciatic  nerve.  .1,  Outside  fixed  iron  and 
sole  plate  with  stoplock  reversed  thus  permitting  dorsiflexion  and  preventing  calcaneus  deformity; 
/},  shoe  to  illustrate  shape  of  ankle  strap  and  proper  site  for  elevation  on  sole  and  heel.  (Stookey, 
Surg.,  Gyn.  and  Obst.,  iqiS.) 

(Sec  Fig.  192.)  \  slight  beiul  to  the  side  bar,  together  with  an  inside  leather 
support  sewed  to  the  shoe,  as  well  as  a  lift  on  the  inner  border  of  the  sole  and 
Ir-cI  will  de\'iatc  body  weight  to  the  mechanically  stronger  outer  arch  and  correct 


412       SURGICAL    AXD    MECHANICAL    TREATMENT     OF    PERIPHERAL    NERVES 

the  tendency  to  valgus.  Inside  the  shoe  an  arch  plate  should  be  worn  to  offer 
support  to  the  arches. 

In  paralysis  of  the  peroneal  and  tibial  divisions,  weakening  of  the  arches  of 
the  foot  may  be  found.  Perhaps  Whitman's  inside  metal  plates  could  not 
be  indicated  more  clearly  than  in  these  cases,  yet  they  are  rarely  employed, 
because  as  long  as  the  loss  of  sensation  persists  no  painful  symptoms  of  the 
condition  are  noted.  A  plaster  cast  or  dental  wax  imprint  of  the  foot  should  be 
taken  and  a  plate  made.  Great  care  must  be  used,  since,  if  the  plate  is  not 
properly  fitted,  pressure  sores  may  develop  without  warning  due  to  the  loss  of 
sensation.     With  care  trophic  changes  may  be  avoided. 

By  walking  without  a  proper  splint,  relaxed  paralyzed  muscles  become  over- 
stretched and  the  effect  of  prolonged  splinting  may  be  undone.  At  night  the 
muscles  should  not  be  left  without  some  support  since  the  weight  of  the  bed 
clothes  may  cause  constant  overstretching.  A  Jones  clubfoot  splint  should  be 
worn  or  a  light  plaster  dorsal  gutter  splint  made.  The  latter  type  will  be  found 
very  satisfactory  since  they  can  be  made  so  as  to  tit  each  individual  and  by 
baking  can  be  made  very  hard  and  light  with  less  plaster  used. 

Comment. — In  injuries  of  the  sciatic  nerve  the  peroneal  division  is  more 
frequently  involved.  Many  times  the  gross  appearance  of  the  tibial  division 
would  seem  to  indicate  a  lesion  as  severe  or  even  more  severe  than  that  of  the 
peroneal,  yet  conductivity  may  be  present  in  the  former  and  totally  inter- 
rupted in  the  latter.  This  peculiar  vulnerability  of  the  peroneal  division  was 
observed  in  the  Russo-Japanese  War,  the  Balkan  W^ars  and  the  World  War, 
and  is  seen  not  only  in  injuries  but  also  in  systemic  toxins  such  as  alcohol, 
diphtheria,  beri  beri,  etc.,  where  the  neuraxes  of  the  peroneal  division  are 
involved,  while  those  of  the  tibial  may  escape.  In  support  of  the  view  that 
functions  and  structures  of  more  recent  acquisition  are  more  readily  lost  and 
more  vulnerable,  it  is  perhaps  significant  that  increased  vulnerability  should  be 
found  in  both  the  peroneal  and  musculospiral  nerves,  both  of  which  supply 
functions  and  muscles  of  more  recent  acquisition. 

Peroneal  Nerve. — As  the  peroneal  nerve  winds  around  the  head  of  the 
fibula,  or  as  it  leaves  the  popliteal  space  it  is  especially  liable  to  direct  injury. 
Because  of  its  exposed  position  indirect  injury  frequently  occurs  and  inclusion 
of  the  nerve  in  callus  in  fractures  of  the  fibula  is  not  uncommon.  The  exposed 
position  of  the  nerve  accounts  not  only  for  the  frequency  with  which  it  is 
injured  but  also,  in  a  measure,  for  the  poor  results  following  suture  of  the 
nerve  in  this  region.     Due  to  the  anatomical  arrangement  of  the  tissues  it  is 


THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  4I3 

frt-ciiR'ntlv  imiJossibk'  to  makf  a  iu-\v  bed  for  the  nerve,  or  to  free  the  nerve 
sufficient  distally  to  permit  mobilization  of  the  distal  segment  to  more 
favorable  surroundings.  The  unfavorable  results  of  suture  in  this  region 
are  somewhat  comparable  to  the  poor  results  obtained  in  suture  of  the  ulnar 
ner\e  when  the  line  of  suture  is  in  the  groove  behind  the  medial  condyle.  It  is 
possible  that  the  poor  nerve  bed  in  these  two  situations  is  not  alone  responsible 
for  the  results  obtained,  but  the  continuous  slight  trauma  due  to  flexion  of 
the  leg  and  of  the  forearm  may  also  contribute  to  interference  with  regenera- 
tion. In  suture  of  the  ulnar  nerve  at  the  elbow  the  results  are  better  with 
transposition  than  without,  even  when  the  nerve  bed  behind  the  condyle  is 
smooth  and  contains  no  callus.  Constant  slight  trauma  to  the  nerve  at  the 
[)oint  of  suture  may  interfere  with  regeneration  as  similar  relatively  slight 
continuous  trauma  may  interfere  with  normal  nerve  conductivity  and  lead, 
eventually,  to  structural  changes  in  the  nerve  fiber.  Another  possible  cause 
of  failure  in  regeneration  in  injuries  of  this  region  is  the  fact  that  final  arrange- 
ment of  the  nerve  fibers  within  the  trunk  has  already  taken  place  for  distribu- 
tion to  the  three  branches  which  arise  at  this  level.  Consequently  misdirection 
and  crossing  of  the  fibers  here  would  be  apt  t(_)  cause  more  permanent  distor- 
tions, leaving  little  opportunity  for  rearrangement  of  the  neuraxes.  However, 
through  its  three  Ijranches,  the  nerve  supplies  a  physiological  unit  serving 
functions  closely  alike  and  not  concerned  in  finer  movements;  consequently 
bad  shunting  alone  of  the  nerve  fibers  should  not  entail  any  great  physiological 
inconvenience. 

Injury  of  the  tibial  nerve  in  the  calf  may  cause  very  few  apparent  motor 
changes,  since  the  long  flexors  of  the  ankle  and  toes  will  have  already  received 
their  innervation,  and  only  the  small  muscles  of  the  sole  of  the  foot  will  be 
paralyzed.  For  this  reason  injuries  to  the  tibial  nerve  in  this  region  may  be 
overlooked,  if  only  a  superficial  examination  be  made,  but  the  cutaneous  anes- 
thesia and  analgesia  in  the  sole  of  the  foot  are  characteristic.  In  incomplete 
injuries  of  the  tibial  nerve  causalgia  and  oilier  jiainful  conditions  are  not  infre- 
quently found,  even  when  the  injury  is  as  low  as  the  middle  third  of  the  leg. 
The  internal  and  external  plantar  nerves  are  rarely  injured  but  they  may  be  the 
source  of  intractable  pain,  due  to  compression  or  inclusion  by  callus  in  fractures 
of  the  tarsal  and  metatarsal  bones.  Painful  symptoms  and  trophic  disturb- 
ances in  the  sole  of  the  foot  in  these  cases  may  be  relieved  by  nerve  hberation  of 
either  ihc  internal  ]ilantar,  external  i)iantar  or  posterior  tibial  nerve,  or  by 
alcohol  injection. 

By    flexion   of   the   knee    the   ends   of   the   sciatic  nerve  can  usually  be 


414         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


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41 6         SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 


brought  together,  but  when  the  loss  of  nerve  substance  is  great,  or  in  conditions 
such  as  ankylosis  of  the  knee-joint,  contractures  in 
muscles  and  tendons  about  the  joint  which  interfere 
with  flexion,  approximation  may  be  impossible,  even 
after  free  exposure  and  moderate  traction.  Due  to  the 
great  size  of  the  sciatic  nerve  a  cable  graft  that  would 
cover  the  entire  cross  area  of  the  nerve  and  afford  an 
approximate  number  of  conducting  tubules  for  the 
neuraxes  is  very  difficult  to  accomplish.  If  grafts  of 
large  diameter  are  used  the  cross  areas  are  better  cov- 
ered, but  experimentally,  at  least,  the  large  grafts  do 
not  transmit  neuraxes  well  through  their  central  por- 
tions. Consequently,  though  a  greater  proportionate 
number  of  tubules  are  offered  only  those  at  the  circum- 
ference of  the  graft  are  utilized. 

Separate  suture  of  either  the  peroneal  or  tibial  division 
of  the  sciatic  may  be  done  without  interfering  with  the 
function  of  the  other.  If  there  has  been  some  loss  of 
nerve  substance  the  intact  nerve  will  of  necessity  be 
longer  than  the  sutured  nerve  so  that  some  angula- 
tion of  the  intact  nerve  may  occur.  By  separating 
the  two  divisions  a  little  distance  above  and  below 
the  suture  a  sharp  kink  is  not  apt  to  form,  and  so  far 
as  my  experience  goes,  the  function  of  the  intact  nerve 
is  not  thereby  interfered  with.  When  the  entire  nerve 
is  sutured  it  is  advisable  to  separate  the  peroneal  and 
tibial  divisions  and  do  a  separate  suture  of  each,  so  as  to 
obtain  more  accurate  apposition  of  the  nerve  ends. 
Suture  of  the  peroneal  nerve  in  the  thigh  offers  a  better 
prognosis  than  suture  of  the  tibial  at  the  corresponding 
level,  and,  in  both,  suture  in  the  intermediate  zone, 
where  the  funiculi  are  grouped  into  larger  bundles,  is 
more  successful  than  suture  in  the  upper  or  lower  nerve 
plexus.  Separate  suture  of  the  individual  nerve  bun- 
dles, asLangley  and  Hashimoto havepointed out, maybe 
done,  particularly  in  the  lower  third  of  the  peroneal  and  tibial  divisions,  and 
misdirection  of  the  fibers  thus  minimized.     In  my  experience  such  suture  has 


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THE    SCIATIC    NERVE    AND    ITS    DIVISIONS  417 

apparently  not  been  followed  by  detrimental  effects  attributable  to  hemorrhage 
or  scar  formation.  Obviously  the  greatest  gentleness  is  needed,  and  a  minimum 
of  handling  of  the  nerve  bundles  is  imperative. 

The  time  of  regeneration  in  sciatic  nerve  injuries  may  be  nearly  twice  as 
long  as  in  other  nerves  and  may  not  be  complete,  in  high  sciatic  sutures,  until 
the  end  of  the  third  year.  The  increased  time  required  is  rather  to  be  expected 
when  one  considers  the  distance  which  the  neuraxes  must  grow  in  high  sciatic 
injuries  and  the  distance  from  the  cells  of  origin  if  the  injury  is  in  the  leg  or 
lower. 

When  nerve  suture  cannot  be  done  or  when  nerve  regeneration  has  failed, 
foot-drop  may  be  satisfactorily  overcome  by  tendon  h.xation,  as  advocated 
by  Robert  Jones  and  McMurray,  and  is  to  be  recommended  highly.  The 
pcronaeus  brevis  and  tibialis  anticus  tendons  are  passed  through  a  hole  drilled 
in  the  tibia  and  h.xed,  thus  holding  the  foot  in  dorsiflexion  above  a  right  angle. 

REFERENCES 

Ansinn,  O.:  Fascien  implantation  bei  Radialis  und  Peroncuslahmung,  Beitr.  z.  klin.  Chir., 
V.  105:  igiy,  pp.  587-593- 

Brocwf.r,  B.:  The  significance  of  phylogenetic  and  ontogenetic  studies  for  the  neuro- 
pathologist, J.  Nerv.  &  Ment.  Dis.,  v.  51:  Feb.,  1920,  p.  113. 

Cheorier,  L.:  Quelques  resuhats  eloignes  d'interventions  nerveuses  sur  le  sciatique  popUte 
externe  (statistique  integrale),  Rev.  Neurol.,  v.  24:   IQ17,  p.  284. 

GiLLERT,  E.:  Uber   ischamische    Muskelkontrakturen,    .\rch.  f.  klin.  Chir.,  v.   112:   1020, 

P-  4i4-4,?i- 
Heile,   B.:  Operative    P'reilegung   dcr  verletzten  peripheren  Nerven,  Beitr.  z.  klin.  Chir., 

V.  108:   1917,  p.  82. 
Hoffman:  Die   Freilegung  des  N.  ischiadicus  im  subglutalen    Teil.,  Zentralbl.  f.  Chir.,  v. 

44:  1917,  p.  159. 
KoKlG,  F.:  Die  Freilegung  des  N.  ischiadicus  in  seinem  obersten  Teile,  Zentralbl.  f.  Chir., 

V.  43-2:  1916,  p.  1023. 
KtJNZEL,  I.:  Zur  Prognose  der  Nerven  Schussverletzungen,  Beitr.  z.  klin.  Chir.,  v.   107: 

1918,  p.  5S3. 
1    La.s'glev.  J.  X.  and  Hashimoto,  M.:  On  the  suture  of  separate  nerve  bundles  in  a  nerve 
I  trunk  and  on  internal  nerve  plexuses,  Jour.  Physiol.,  v.  51:   1917,  p.  318. 

!    NiENY:  Einfache    Slutzen    fur   Peroneuslahmungen,    Miinchen.    mcd.    Wchnschr.,    v.    63: 

(No.  2),  1916,  p.  68. 
Perrone,   G.   anil  T.w  IKAM,  G.:  Contril)ulo  alia  topogralia  fascicolare  dello  sciatico  pop- 

liteo  esterno  in  un  caso  di  lesione  isolala  del  nervo  muscolo  cutaneo  in  prossimita  del: 

collo  del  peronco.  La  chirurgia  degli  Organi  Mov.,  v.  3:   1919,  p.  332. 


4lS         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

PoiRlER,  P.  and  Chaepy,  A.:  Traite  d'Anatomie  Humaine,  Paris,  Masson  et  cie.,  1899, 

p.  lii. 
Stopford,  J.  S.  B.:  The  results  of  secondarv'  suture  of  peripheral  nerves.  Brain,  v.  43:  pt.  i, 

1920,  p.  I. 
Worster-Deought,  C:  Lesions  of  the  posterior  tibial  nerve.  Brain,  v.   44:  pt.  i,  1921,  p.  5. 


CHAPTER  XVIII 

NERVES  INFREQUENTLY  INJURED 
RECURRENT  LARYNGEAL  NERVE 

The  recurrent  laryngeal  nerve  may  be  injured  by  bullet  or  stab  wounds  and 
during  operative  proceedings.  Besides  these,  peripheral  paralysis  may  be  due 
to  pressure  by  tumors  of  the  neck  and  thorax  as  well  as  by  pressure  on  the  nerve 
by  the  heart  and  the  aorta.  Ortner  (1897),  Guttman  and  Neuhof  (1916), 
Rosenthal  (1916),  Brown  and  Hempstead  (1918)  have  called  attention  to 
paralysis  as  result  of  jiressurc  of  the  dilated  auricle  against  the  aorta  in  mitral 
stenosis. 

Suture  of  the  Recurrent  Laryngeal  Nerve. —  Suture  of  the  recurrent  laryn- 
geal nerve  was  reported  by  Stierlin  (1907).  He  was  able  to  obtain  end-to-end 
suture  and  complete  functional  return  was  found  sLx  years  later  with  only  a 
slight  lagging  of  the  vocal  cord  on  the  operated  side  to  indicate  the  former 
paralysis.  Shelton  Horsley  (1910)  described  a  successful  suture  of  the  recurrent 
laryngeal  nerve  three  months  after  the  nerve  had  been  severed  by  a  bullet.  In 
suturing  the  ner\e  he  made  "an  incision  along  the  anterior  border  of  the  left 
sternocleidomastoid  muscle.  The  center  of  the  incision  corresponded  to  the 
lower  limit  of  the  larynx.  The  sternomastoid,  together  with  the  carotid 
artery  and  jugular,  was  retracted  toward  the  left.  The  left  lobe  of  the  thyroid 
gland  was  exposed  and  was  retracted  along  with  the  trachea  and  larynx  to  the 
right.  The  recurrent  laryngeal  nerve  was  identified,  where  it  runs  in  the  groove 
between  the  trachea  and  the  esophagus.  It  was  found  to  be  injured  just  before 
its  entrance  into  the  larynx,  and  was  involved  in  a  small  mass  of  scar  tissue 
where  the  l)ull(t  had  ex  idently  grazed  the  nerve.  The  diseased  portion,  approxi- 
mately a  third  of  an  inch  in  length,  was  excised,  leaving  a  small  filament,  which 
was  probably  the  posterior  portion  of  the  sheath  of  the  nerve  with  a  few  fibers 
that  had  escaped  flirect  injury.  The  proximal  part  was  freely  loosened  to 
relieve  tension  and  the  nerve  sutured  with  No.  o  twenty-day  chromic  catgut  in 
a  fine  cur\  ed  lu'edle.     Some  muscular  tissue  was  drawn  over  the  sutured  nerve." 

One  year  later  almost  perfect  mobility  of  the  affected  side  was  present 
with  only  slight  lagging,  especially  in  adduction.  Adhesions  between  the 
anterior  thirds  of  bolh  vocal  cords  had  formed,  possibly  the  result  of  their  close 
proximity  during  the  jjcriod  of  paralysis.     The  volume  of  the  voice  was  dimin- 

410 


420 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


ished,  not  as  a  result  of  a  failure  in  re-establishment  of  motor  power  of  the  laryn- 
geal muscles  but  rather  due  to  the  mechanical  narrowing  of  the  aperture. 

Direct  Implantation  of  the  Recurrent  Laryngeal  Nerve.- — Hoessly  (1916) 
has  shown  experimentally  that  neurotization  of  the  laryngeal  muscles  may  take 
place  by  direct  nerve  implantatoin  by  the  method  of  Hacker  (1914),  Heinicke 


Fig.  193. — Operation  showing  direct  implantation  of  motor  branch  of  spinal  accessory  into 
thyreoarytenoid  muscle  for  recurrent  laryngeal  paralysis,  a,  M.  Thyreo-arytenoideus;  b,  M,  crico- 
arytenoideus  lateralis;  c,  M.  sternocleidomastoideus;  d,  JI.  thyreohyoideus;  e,  M.  sternohyoideus  and 
omohyoideus;/,  M.  cricothyreoideus;  g,  M.  sternothyreoideus.     (Hoessly,  Beitr.  z.  klin.  Chir.,  1916.) 


(1914),  Erlacher  (1914).  A  branch  of  the  spinal  accessory  was  implanted  into 
the  lateral  crico-arytcnoid  muscle  and  thyreo-arytcnoid  in  three  dogs  after 
excision  of  6  cm.  of  the  recurrent  laryngeal  ner\'e.  Five  months  later  two  of 
the  three  dogs  showed  normal  phonation  and  very  little  difference  in  the  anat- 
omical position  of  the  vocal  cords,  whereas  immediately  following  the  opera- 
tion the  cord  on  the  affected  side  was  found  to  be  in  the  cadaveric  position 
Histological  examination  of  the  muscles  thus  neurotized  showed  motor  end 
plates  and  nerve  fibers,  while  the  remaining  muscles  supplied  by  the  recurrent 
laryngeal    nerve    showed    degeneration    and    no    nerve   fibers,    thus   showing 


NERVES   INFREQUENTLY    INJURED  4  21 

that    spontaneous    regeneration    of    the    recurrent    hiryngeal    nerve    had    not 
taken  [)lace. 

Hoessly  believed  that  this  method  of  neurotization  of  the  laryngeal  muscles 
might  be  utilized  and  suggested  the  following  operative  technic.  (See  Fig.  193.) 
"Local  anesthesia  similar  to  that  employed  for  thyroid  operations.  Collar 
incision.  Blunt  dissection  along  the  lateral  border  of  the  small  neck  muscles. 
The  hyothyroid  muscle  is  cut  at  its  base.  The  thyroid  cartilage  is  thus  exposed 
and  easy  access  afforded  when  the  larynx  is  retracted  to  the  opposite  side  by 
means  of  sharp  retractors.  A  window  is  then  cut  into  the  ala  of  the  thyroid 
cartilage  at  the  level  of  the  muscles  to  be  neurotized  and  a  branch  of  the  spinal 
accessory  to  the  sternocleidomastoid  muscle  is  taken  and  the  central  end 
implanted  into  the  small  muscles  of  the  larynx  and  fixed  with  catgut.  The  site 
of  the  implantation  is  then  covered  with  a  flap  of  fatty  tissue,  the  window  closed 
and  the  wound  sutured  in  the  usual  manner." 

SPINAL  ACCESSORY  NERVE 

The  spinal  accessory  nerve  may  be  injured  in  gunshot  and  stab  wounds  or 
in  operations  for  removal  of  tumors  in  the  neck,  tubercular  glands  or  a  cervical 
rib.  When  the  nerve  is  injured  near  its  point  of  entrance  into  the  trapezius 
the  paralysis  of  this  muscle  is  more  marked  than  when  the  nerve  is  injured  near 
its  exit  from  the  cranial  cavity  since  it  receives  contributions  from  the  third 
and  fourth  cervical  nerves  lower  down.  In  injuries  of  the  nerve  near  its  exit, 
as  compared  with  those  at  a  lower  level  which  I  have  seen,  there  has  been  no 
appreciable  difference  in  the  extent  of  the  paralysis  or  the  deformity. 

As  the  spinal  accessory  nerve  makes  its  exit  from  the  jugular  foramen  it 
may  be  one  of  the  three  or  four  nerves  to  be  injured  in  the  retroparotid  space. 
Vernet  (1917)  has  described  as  the  syndrome  of  the  foramen  lacerum,  injuries 
involving  the  glossopharyngeal,  vagus  and  spinal  accessory  nerves,  and  Villaret 
(191 7)  the  syndrome  of  tlic  rclroparolid  spare  when  the  injury  involves  not  only 
the  glossopharyngeal,  vagus  and  spinal  accessory  but  the  hypoglossal  and 
cervical  sympathetic  as  well.  Pollock  (1920)  has  described  additional  cases 
involving  some  of  these  nerves.  It  will  be  recalled  that  immediately  after  their 
exit  these  nerves  are  close  together  and  that  the  hypoglossal  nerve  lies  medial  to 
the  spinal  accessory  and  winds  around  the  cervical  sympathetic,  glossopharyn- 
geal and  vagus  nerves  from  behind  forward  and  downward,  hence  injury  in 
this  region  may  inxolve  any  or  all  of  these  nerves. 


42  2         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Anatomy. — The  spinal  accessory  nerve  arises  by  five  or  six  rootlets  from  the 
upper  five  or  six  cervical  segments.  The  cells  lie  in  the  lateral  or  splanchnic 
motor  column  of  the  ventral  gray.  The  accessory  portion  arises  from  a  con- 
tinuation upward  into  the  medulla  of  the  same  column  of  cells  and  is  incorpor- 
ated in  the  vagus,  joining  it  immediately  at  its  exit  from  the  cranial  cavity  and 
consequently  has  no  representation  in  the  peripheral  distribution  of  the  spinal 
accessory  nerve.  The  spinal  accessory  nerve  is  distributed  to  the  sternocleido- 
mastoid and  trapezius  muscles,  supplying  the  former  completely  in  junction 
with  the  third  and  fourth  cervical  nerves. 

Coixrse. — Each  rootlet  of  the  spinal  portion  joins  with  the  rootlet  above  to 
form  the  intradural  portion  of  the  nerve  lying  in  the  subarachnoid  space  between 
the  dentate  ligament  and  the  dorsal  roots.  The  nerve  thus  formed  enters  the 
cranial  cavity  through  the  foramen  magnum  and  makes  its  exit  through  the 
jugular  foramen  in  company  with  the  ninth  and  tenth  nerves  and  the  internal 
jugular  vein. 

In  the  neck  the  nerve  is  directed  downward,  outward  and  backward  passing 
behind  the  transverse  process  of  the  atlas,  beneath  or  through  the  sterno- 
cleidomastoid— rarely  superficial  to  this  muscle — to  enter  the  dorsal  triangle 
of  the  neck  where  it  lies  rather  superficial,  being  covered  only  by  skin  and  the 
cervical  fascia  and  enters  the  trapezius  muscle  on  its  under  surface. 

Variations.^Occasionally  the  spinal  accessory  nerve  apparently  communi- 
cates with  the  dorsal  roots  of  the  first  and  second  cervical  nerves  and  possesses 
a  dorsal  ganglion.  These  communications  and  ganglia  have  aroused  con- 
siderable interest  since  this  nerve  is  entirely  motor  so  far  as  its  cells  of  origin  are 
concerned,  and  no  peripheral  sensory  distribution  has  been  found.  The  commu- 
nication with  the  dorsal  roots  and  the  presence  of  the  ganglia  represent  merely 
a  superficial  fusion  over  an  extremely  short  course  where  the  spinal  accessory 
nerve  passes  close  to  the  dorsal  roots,  the  fibers  of  each  remaining  distinct. 
In  one  instance  the  spinal  accessory  nerve  on  both  sides  ended  in  the  sterno- 
cleidomastoid and  the  trapezius  muscle  was  supplied  by  the  third  and  fourth 
cervical  nerves  only  (Curnow).  While  this  may  suggest  the  importance  of  the 
contribution  of  the  third  and  fourth  cervical  nerves  to  the  spinal  accessory, 
such  innervation  of  the  trapezius  is  difiicult  to  interpret  on  a  developmental 
basis  since  the  cervical  nerves,  somatic  motor  in  origin,  should  not  supply 
splanchnic  musculature  such  as  the  trapezius. 

Defonnity. — In  injuries  of  the  spinal  accessory  nerve  both  the  sterno- 
cleidomastoid and  the  trapezius  are  paralyzed,  the  former  completely  and  the 


NERVES    INFREQUENTLY    INJURED  423 

latter  partially,  but  it  is  only  in  extremely  rare  instances  that  the  trapezius 
receives  sufficient  innervation  from  the  cervical  nerves  to  permit  contraction 
functionally  efficient.  In  the  cases  of  spinal  accessory  paralysis  the  author 
has  seen,  no  contraction  of  the  trapezius  muscle  could  be  detected,  but  some 
observers  have  found  a  partial  paralysis  only.  Schultz  believes  that  it  is  only 
the  lower  part  of  the  trapezius  which  is  supplied  exclusively  by  the  cervical 
nerves. 

In  paralysis  of  the  trapezius  the  contour  of  the  neck  is  altered,  due  to  an 
increase  in  the  angle  formed  by  the  shoulder  and  neck.  The  shoulder  on  the 
affected  side  is  lower,  the  vertebral  border  of  the  scapula  more  prominent, 
the  inferior  angle  approaches  the  midline  and  is  turned  toward  the  opposite 
side  in  place  of  directly  downward. 

The  functional  loss  in  the  mtnements  of  the  arm  may  be  relatively  slight, 
and  in  long-standing  paralysis  the  disability  is  in  a  great  measure  compensated. 
The  function  of  the  trapezius  muscle  varies  according  to  the  position  of  the  arm, 
the  movement  performed  and  whether  the  whole  muscle  or  only  part  of  the 
muscle  contracts.  By  a  muscle  of  such  wide  origin  a  great  variety  of  functions 
are  served.  The  clavicular  portion  elevatej  the  scapula  as  a  whole  and  raises 
the  shoulder  during  inspiration — an  accessory  respiratory  muscle.  It  also  helps 
to  draw  the  head  backward  and  turn  the  chin  toward  the  opposite  side.  The 
I  middle  portion  elevates  the  scapula,  draws  its  vertebral  border  toward  the  mid- 
)  line,  and  rotates  its  outer  angle  upward.  The  lower  portion  moves  the  scapula 
inward  and  helps  to  fix  it  during  arm  movements,  and,  when  acting  alone, 
rotates  the  outer  angle  downward.  When  the  muscle  acts  as  a  whole  the 
scapula  is  fixed,  thus  rendering  the  action  of  the  muscles  moving  the  arm  more 
efficient. 

Mechanical  Treatment. —  No  form  of  splinting  is  of  real  value.  In  in- 
operable cases  efforts  should  be  directed  to  re-educate  the  muscles  associated 
with  the  trapezius  in  the  movements  of  the  shoulder  and  arm,  particularly 
the  rhomboideii,  levator  scapulas,  serratus  anticus,  clavicular  head  of  the 
pecloralis  major,  deltoid  coracobrachialis  and  biceps.  If  these  muscles  are 
developed  the  limitation  of  movement  in  spinal  accessory  paralysis  will  be 
relatively  slight. 

Exposure. —  The  exposure  of  the  spinal  accessory  nerve  has  been  described 
under  the  facial  nerve  (see  page  212).  If  the  spinal  accessory  nerve  is  injured 
more  distally,  that  is,  after  its  entrance  into  the  dorsal  triangle  of  the  neck,  it 
mav  be  extremelv  diflicull  to  lind  it,  since  the  nerve  is  small  and  mav  be  con- 


424         SURGICAL   AND    MECHANICAL   TREATMENT    OF   PERIPHERAL   NERVES 

fused  with  the  cervical  nerves  in  this  region.  Identification  by  the  electrode 
unfortunately  may  not  be  possible  if  the  nerve  is  injured.  The  surest  way  of 
finding  the  nerve  is  to  begin  centrally  and  trace  it  downward.  However,  in 
complete  interruption,  particularly  with  loss  of  substance,  the  distal  end  can 
rarely  be  found.  In  these  cases  an  attempt  should  be  made  to  implant  the 
central  end  directly  into  the  trapezius  muscle.  This  method  has  not  been  very 
successful  in  this  muscle,  probably  due  to  the  transverse  or  oblique  direction  of 
the  muscle  libers,  allowing  only  a  small  portion  of  the  muscle  to  be  innervated; 
not  suflicient  for  function. 

LONG  THORACIC  NERVE 

The  long  thoracic  nerve  is  rarely  in\-olved  in  brachial  plexus  injuries, 
unless  complete  evulsion  of  the  cervical  roots  has  occurred,  since  the  nerve 
arises  from  the  cervical  roots  immediately  after  their  exit  from  the  interverte- 
bral foramina.  Isolated  paralysis  has  been  seen  from  carrying  heavy  weights  on 
the  shoulder  and  in  stab  wounds  and  gunshot  wounds,  but  this  is  extremely 
rare.  In  one  case  the  long  thoracic  nerve  was  injured  relatively  high  in  the 
neck.  Complete  paralysis  of  the  serratus  anticus  followed  with  marked  winging 
of  the  scapula  and  an  unusual  degree  of  downward  rotation  of  the  external  angle 
so  that  the  long  axis  of  the  scapula  was  directed  almost  transversely.  Some 
months  after  the  injury  complete  paralysis  of  the  muscles  supplied  by  the 
suprascapular  nerve  appeared.  It  was  felt  that  this  late  paralysis  in  the  dis- 
tribution of  the  suprascapular  nerve  resulted  from  the  marked  rotation  of  the 
scapula  and  was  caused  by  pressure  exerted  on  the  nerve  as  it  passed  through  the 
suprascapular  notch.  So  far  as  I  am  aware  such  a  mechanism  for  injury  of  the 
suprascapular  nerve  is  most  unusual. 

Anatomy. — The  long  thoracic  nerve  arises  as  dorsal  branches  from  the 
ventral  divisions  of  the  fifth,  sixth  and  seventh  cervical  nerves,  immediately 
after  their  exit  from  the  intervertebral  foramina.  The  nerve  pierces  the 
scalenius  medius  muscle  in  two  bundles  and  descends  behind  the  brachial 
plexus,  crossing  over  the  upper  digitation  of  the  serratus  anticus  to  enter  the 
axilla  between  the  serratus  anticus  and  the  axillary  artery.  It  descends  on  the 
outer  surface  of  the  serratus  anticus  and  supplies  separate  branches  to  each 
digitation. 

Deformity. — In  total  paralysis  of  the  serratus  anticus  the  scapula  assumes 
a  characteristic  position  with  the  entire  scapula  drawn  away  from  the  chest 
wall,  so  much  so  that  in  some  cases  the  hand  can  be  inserted  between  the  scapula 


NERVES    INFREQUENTLY    INJURED  425 

and  the  thorax.  The  scapuhi  is  rotated  so  that  the  inferior  angle  is  directed 
transversely  and  the  outer  angle  downward  and  forward.  This  position  of 
the  scapula  is  due  mainly  to  the  weight  of  the  upper  extremity  and  the  lack 
of  support  for  the  scapula.  The  arm  can  rarely  be  elevated  beyond  the  hori- 
zontal, and  there  is  marked  disability  in  attempts  to  carry  weights,  due  to 
the  fact  that  the  scapula  is  no  longer  a  fixed  point  for  the  action  of  the  shoulder 
girdle  muscles.  The  arm,  however,  can  be  raised  beyond  a  horizontal  by  the 
deltoid  provided  the  arm  is  assisted  in  elevation  to  above  no  or  115°. 

Mechanical  Treatment. — The  shoulder  should  be  maintained  in  elevation 
by  an  axillary  pad  or  an  abduction  splint  and  pressure  should  be  exerted  upon 
the  scapula  to  maintain  it  against  the  chest  wall.  By  elevation  of  the  arm 
the  marked  rotation  of  the  scapula  is  prevented  and  the  danger  of  injury  to 
the  suj)rascapular  nerve  is  avoided.  If  the  scapula  be  held  against  the  chest 
wall  rotation  of  the  scapula  and  elevation  of  the  arm  can  be  accomplished,  by 
action  of  the  associated  muscles,  especially  the  trapezius,  rhombodeii  and  leva- 
tor scapulae.  By  being  held  against  the  chest  wall  the  scapula  may  be  used 
as  a  fixed  point  for  the  action  of  the  other  muscles — an  important  factor  in  the 
mechanics  of  shoulder  and  arm  movements. 

Exposure. — The  long  thoracic  nerve  may  be  exposed  above  the  clavicle  by 
the  same  incision  as  for  the  brachial  plexus.  The  nerve  will  be  found  lying 
behind  the  plexus,  but  if  difficulty  is  encountered  in  finding  it,  it  may  be  picked 
up  at  its  origin  as  it  emerges  through  the  scalenius  medius  muscle  and  then 
traced  downward.  By  elevation  of  the  shoulder  and  bending  the  head  laterally 
a  considerable  loss  of  nerve  substance  can  be  overcome.  Attempts  to  implant 
the  central  end  directly  into  the  serratus  anticus  is  of  little  value,  since  only 
the  digitations  into  which  the  nerve  is  implanted  would  be  innervated.  Each 
digitation  is  more  or  less  a  separate  unit,  normally  supplied  by  a  separate  nerve 
branch,  and  neuraxes  from  the  implanted  nerve  would  very  likely  be  unable  to 
extend  to  other  digitations. 

SUPRASCAPULAR  NERVE 

Isolated  paralysis  of  the  suprascapular  nerve  is  most  uncommon,  while 
I  involvement  of  this  nerve  in  brachial  plexus  injuries  is  extremely  frequent; 
rupture  of  the  outer  cord  occurring  at  about  the  point  at  which  the  supra- 
scapular nerve  is  given  oft".  (See'Figs.  96,  97.)  Like  the  long  thoracic  nerve 
the  suprascapular  nerve  may  be  injured  in  carrying  heavy  weights  upon  the 
shoulder  and  rarely  in  stab  and  gunshot  wounds.     It  has  been  injured  in  sudden 


426         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

wrenching  of  the  arm  and,  as  has  been  pointed  out,  as  an  associated  paralysis 
in  paralysis  of  the  long  thoracic,  due  to  injury  of  the  nerve  in  the  supra- 
scapular notch  by  extreme  rotation  of  the  scapula. 

Anatomy. — The  suprascapular  nerve  arises  from  the  outer  cord  of  the 
brachial  plexus,  close  to  or  at  the  junction  of  the  fifth  and  sixth  cervical  roots. 
The  nerve  is  relatively  large,  lies  above  the  outer  cord  and  between  it  and  the 
long  thoracic  nerve;  crosses  over  the  first  digitation  of  the  serratus  anticus 
and  behind  the  clavicle,  turns  lateral  along  the  upper  margin  of  the  pectoralis 
minor,  together  with  the  suprascapular  artery,  enters  the  suprascapular  notch, 
and  is  distributed  to  the  supraspinatus  and  infraspinatus  muscles. 

Deformity. — In  injuries  of  the  suprascapular  nerve  atrophy  of  the  supra- 
spinatus and  infraspinatus  muscles  is  seen  with  characteristic  depressions 
above  and  below  the  spine  of  the  scapula.  Due  to  paralysis  of  these  muscles, 
external  rotation  of  the  arm  is  lost.  Some  observers  have  described  external 
rotation  due  to  the  action  of  the  teres  minor  muscle,  but  this  the  author  has  not 
been  able  to  verify  in  any  of  his  cases.  However,  slight  external  rotation  may 
be  accomplished  by  action  of  the  scapular  portion  of  the  deltoid,  but  this  is 
possible  only  when  the  arm  is  held  horizontal,  and  none  occurs  with  the  arm  at 
the  side.  According  to  Duchenne  (1867)  the  supraspinatus  acting  alone  holds 
the  humerus  against  the  glenoid  fossa.  With  the  arm  raised  above  a  right  angle 
it  also  helps  in  elevation  of  the  humerus.  The  loss  of  external  rotation  is 
important  since  without  this  movement  considerable  disability  exists. 

Mechanical  Treatment. — No  mechanical  treatment  is  indicated  and  any 
form  of  adequate  splinting  would  interfere  seriously  with  other  movements 
of  the  arm.  By  passive  motion  and  active  exercises,  contracture  in  internal 
rotation  can  be  avoided. 

Exposure. — Exposure  of  the  suprascapular  nerve  is  that  for  the  brachial 
plexus.     (See  page  249.) 

ANTERIOR  CRURAL  NERVE 

The  close  relationship  of  this  nerve  to  the  great  femoral  vessels  probably 
accounts  for  the  relatively  few  anterior  crural  nerve  injuries  met  with,  since 
probably  the  great  vessels  are  injured  at  the  same  time  and  fatal  hemorrhage 
results.  Immediately  below  the  exit  of  the  anterior  crural  nerve  from  the  pel- 
vis, under  Poupart's  ligament  the  nerve  breaks  up  into  its  numerous  muscular  i 
and  cutaneous  terminal  branches,  so  that  even  if  the  nerve  were  injured  in  this 
region,  end-to-end  suture  would  be  almost  impossible.     If  suture  were  possible 


NERVES    INFREQUENTLY    INJURED 


427 


it  would  be  extremely  diflicult  to  distinguish  the  motor  from  the  sensory 
branches  and  to  avoid  uniting  a  motor  to  a  sensory  nerve.  In  general  the 
muscular  branches  lie  deeper,  usually  arranged  in  three  groups.  An  inner 
group  which  follows  the  medial  border  of  the  long  saphenous  to  where  the  latter 
enters  Hunter's  canal,  supplies  the  vastus  medialis  and  intermedius,  the  branch 
to  the  latter  being  given  off  rather  early  in  its  course.  The  middle  group 
supplies  the  rectus  femoris  and  vastus  e.xternus,  entering  these  muscles  from 
their  under  surface  and  sending  branches  through  to  the  crureus.     The  outer 


Fig.  194. — Thomas  caliper  for  paralysis  of  anterior  crural  nerve.  Note  angle  at  which  caliper 
should  be  inserted  into  shoe  to  obtain  slight  inversion  of  foot.  The  shoe  is  elevated  on  the  inner 
border  so  as  to  deviate  body  weight  and  lessen  the  strain  on  the  knee-joint.  .\  spring  lock  at  the  knee 
may  be  used  lo  [)ermit  tlexion  on  sitting.     (See  p.  407.)     (Stookcy,  Surg.,  Gyn.  and  Obst..  iqiS.) 


group  passes  under  the  sartorius,  supplies  this  muscle  with  both  an  upper 
and  lower  set  of  branches.  The  latter  enters  the  muscle  at  about  its  middle 
third. 

Surgical  Treatment.     As  has  been  said,  suture  of  the  anterior  crural  is 
rarely  possible.     However,  direct  imi^lantation  of  the  central  branches  into  the 
,    muscles   of   the  quadriceps  femoris  may  be  tried,  but  the  most  satisfactory 
I    method    to  overcome  the  deformity  with  complete    paralysis    of   these    mus- 
cles  will   be    tendon    transplantation    either   of   the    biceps   alone   or   of   the 
semitendinosus  or  both. 


428         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Deformity. — The  quadriceps  femoris,  the  sartorius  and  pectineus  muscles 
being  paralyzed,  extension  of  the  leg  is  impossible.  The  patient  walks  with  a 
swinging  gait,  coming  down  upon  the  heel.  By  action  ot  the  tensor  fasciae  lata-, 
supplied  by  the  superior  gluteal  nerve,  the  knee  is  held  locked  in  hyperextension, 
or  in  place  of  locking  the  knee  the  patient  may  walk  bent  over,  the  hand 
resting  heavily  on  the  semiflexed  thigh.  Unless  the  knee-joint  is  guarded  it 
becomes,  a  trigger  joint,  and  by  suddenly  giving  way  may  let  the  patient  fall. 
In  all  neglected  cases  genu  recur\'atum  may  result  due  to  gravity  and  constant 
fixation  of  the  knee  in  hyperextension. 

Mechanical  Treatment. — Stabilizing  the  knee  by  preventing  extreme 
hyperextension  and  the  tendency  to  trigger  joint  formation  can  be  accomplished 
by  a  Thomas  walking  caliper  fitted  with  either  a  stop  or  spring  lock  permitting 
flexion  of  not  more  than  35°.  (See  Fig.  194.)  The  spring  lock  is  very  conven- 
ient since  it  permits  the  knee  to  be  slightly  flexed  while  sitting  and,  by  limiting 
the  degree  of  flexion,  overstretching  of  the  extensors  will  be  avoided.  With 
the  support  of  the  quadriceps  femoris  gone,  strain  on  the  knee-joint  and  weaker 
internal  lateral  ligament  occurs  but  can  be  minimized  by  shifting  the  body 
weight  by  raising  the  shoe  one-third  inch  on  the  inside,  and  by  changing  the 
relative  position  of  the  external  and  internal  bars  of  the  caliper  as  they  fit  into 
the  heel. 

OBTURATOR  NERVE 

Injury  of  this  nerve  is  even  more  rarely  met  with  than  injuries  of  the  ante- 
rior crural,  possibly  for  the  reason  that  fatal  hemorrhage  from  adjacent  large 
vessels,  or  serious  pelvic  injury,  usually  accompanies  injury  to  the  nerve.  Its 
muscular  branches  are  given  oft"  almost  immediately  after  its  exit  from  the  pel- 
vis, have  a  short  extramuscular  course  and  peripheral  paralysis,  therefore,  is 
infrequent. 

Deformity. — Weakness  in  adduction  of  the  thigh  is  due  to  paralysis  of  the 
adductor  longus,  bre\is  and  magnus  as  well  as  the  gracilis.  However,  the  ad- 
ductor longus  is  also  supplied  by  a  small  branch  from  the  anterior  crural  nerve 
and  the  adductor  magnus  by  a  branch  from  the  nerve  to  the  hamstrings.  The 
adductor  magnus  is  formed  from  the  same  primitive  premuscle  mass  as  the 
hamstrings,  hence  its  dual  supply  through  the  obturator  and  the  nerve  to  the 
hamstrings  both  of  which  are  made  up  of  fibers  from  ventral  divisions.  The 
quadratus  femoris  and  lower  fibers  of  the  gluteus  maximus  also  serve  as  adduc- 
tors.    Hence  adduction  is  not  entirely  lost  even  in  complete  obturator  paralysis 


NERVES    INFREQUENTLY    INJURED  429 

due  to  the  dual  nerve  supply  of  the  adductor  longus  and  magnus  and  to  the 
action  of  the  gluteus  maximus  and  part  of  the  quadriceps  femoris. 

Exposure. — The  lower  extremity  is  held  in  extreme  adduction  and  the 
thigh  slightly  flexed  on  the  abdomen  so  as  to  relax  the  medial  muscle  group. 
An  incision  lo  cm.  long  is  made  along  the  medial  border  of  the  adductor  longus, 
beginning  at  the  os  pubis.  After  cutting  through  the  deep  fascia  the  oblique 
space  between  the  adductor  longus  antl  the  pectineus  and  adductor  brevis 
is  opened.  Unless  it  be  recalled  thai  the  pectineus  overlaps  the  adductor 
longus  some  difficulty  may  be  met  with  in  finding  the  fascial  plane  between 
these  two  muscles.  The  adductor  longus  is  retracted  medially  and  the  pec- 
tineus and  adductor  brevis  laterally.  The  medial  border  of  the  adductor 
longus  is  followed  upward  to  its  origin.  At  about  3  cm.  below  this  point  both 
the  superficial  and  deep  branches  of  the  obturator  nerve  may  be  found  as  it 
emerges  from  the  obturator  canal.  In  some  instances  the  deep  branch  pierces 
the  obturator  externus  to  pass  dorsally  between  the  adductor  magnus  and 
adductor  brevis.  If  this  branch  is  not  found  at  the  obturator  canal  it  had 
better  be  ignored  for  it  may  be  very  difficult  to  find  and  it  is  not  of  great  motor 
significance. 

SUPERIOR  AND  INFERIOR  GLUTEAL  NERVES 

Isolated  paralysis  of  the  gluteal  nerves  without  injury  to  the  sciatic  nerve 
is  extremely  uncommon.  These  nerves  arise  separately  from  the  lumbosacral 
plexus  deriving  their  fibers  from  the  dorsal  divisions  of  the  fourth  and  fifth 
lumbar,  first  and  second  sacral  nerves.  Both  gluteal  nerves  leave  the  pelvis 
through  the  sciatic  notch:  the  superior  above  the  pyriformis  along  with  the 
superior  gluteal  artery;  the  inferior  below  the  pyriformis  with  the  inferior 
gluteal  artery  and  sciatic  nerve.  The  superior  gluteal  nerve  runs  between  the 
gluteus  minimus  and  medius,  supplies  the  former  from  its  dorsal  surface  and  the 
latter  from  its  ventral,  and  ends  in  the  tensor  fascia£  lat^-e.  The  gluteus  inferior 
lies  superficial  to  the  sciatic  nerve  and  immediately  after  it  makes  its  exit  from 
beneath  the  pyriformis  muscle  it  l)reaks  up  into  muscular  branches  for  the 
supply  of  the  gluteus  maximus.     (See  Fig.  195.) 

In  injuries  of  the  superior  gluteal  nerve  the  internal  rotators  of  the  thigh, 
namely  the  gluteus  medius  and  minimus,  and  tensor  fasciae  latae  are  paralyzed. 
External  rotation  is  also  weakened  due  to  loss  of  the  action  of  the  dorsal  fibers 
of  the  gluteus  medius  and  minimus.  If  the  inferior  gluteal  is  paralyzed  the 
external  rotator  and  adductor  action  of  the  gluteus  maximus  is  lost. 


430      SURGICAL    AND   MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Exposure. — Both  of  the  gluteal  nerves  may  be  exposed  by  an  incision  begin- 
ning at  the  inferior  spine  of  the  ilium  and  directed  downward  to  three  finger 
breadths  below  the  great  trochanter.     In  certain  cases  the  incision  may  be 


Fig.  195. — Superior  and  inferior  gluteal  nerves.  Surface  projection,  i,  Superior  gluteal  nerve 
to  gluteus  raedius  and  gluteus  minimus;  i',  branch  to  tensor  fascis  lat^;  2,  inferior  gluteal  nerve  to 
gluteus  maximus. 

carried  lower  so  as  to  expose  the  insertion  of  the  gluteus  maximus  muscle  as  is 
done  in  operations  on  the  proximal  third  of  the  sciatic  nerve.  (See  page  395.) 
The  gluteus  maximus  fibers  are  separated  in  the  direction  of  their  course 
until  the  pyriformis  muscle  is  encountered.  By  wide  retraction,  by  cutting 
if  necessary  the  insertion  of  the  gluteus  maximus,  exposure  of  both  the  superior 
and  inferior  gluteal  nerves  may  be  obtained. 


NERVES    INFREQUENTLY    INJURED  43 1 

If  end-to-end  suture  is  impossible  the  proper  procedure  will  depend  on 
the  point  at  which  the  injury  has  occurred.  When  the  injury  is  close  to  where 
the  nerves  emerge  from  the  pelvis  the  distal  segment  should  be  crossed  into  the 
sciatic — the  superior  gluteal  into  the  tibial  portion  and  the  inferior  gluteal  into 
the  peroneal  j^ortion.  If  the  injurj-  be  close  to  the  entrance  of  the  nerve  into 
the  muscle  the  central  segments  should  be  directly  implanted — the  superior 
gluteal  into  the  gluteus  medius  and  the  inferior  gluteal  into  the  gluteus  maximus. 


REFERENCES 

Brown,  G.  E.  and  Hempstead,  B.  E.:  Paralysis  of  the  recurrent  laryngeal  nerve  associaled 

with  mitral  stenosis,  J.  A.  M.  A.,  v.  70:   igi8,  p.  4. 
Bruce,  A.  X.:  Paralysis  of  the  spinal  accessory  nerve  following  many  years  after  removal 

of  tuberculous  glands  of  the  neck.  Rev.  Neurol.  &  Psychiat.,  v.  13:   1915,  p.  51. 
Collet:  Atresias  traumatiques  du  conduit-auditit  gueris  par  I'evidement  petro-mastoidicn, 

Lyon  med.,  v.  125:  1916,  p.  163. 
Paralysie  du  recurrent  par  balle,  Lyon  med.,  v.  124:   1915,  p.  188. 
DuCHENNE  DE  BOULOGNE,  G.  B.  A.:  Physiologie  des  Mouvements,  1867,  J.  B.  Balliere  et 

Fils,  Rue  Hautefeuille,  ig,  Paris. 
Erlacher,  P,:   i.  Hyperneurotisation;  muskuliire  Neurolisation;  freie  Muskeltransplant- 

ation.     E.xperimentelle  Untersuchungen,  Zentralbl.  f.  Chir.,  v.  41:  April,  19:4,  p.  625, 
2.  Ueber   die   motorischer   Nervenendungen,  histologische   und   experimentelle  Beitrage 

zu  den  Operationen  an  den  peripheren  Nerven,  Ztschr.  f.  orthop.  Chir.,  v.  34:    1914. 

p.  561. 
GuTT.MAX,  J.  and  Neuhof,  S.:  Radial  pulse  difference  and  left  recurrent  nerve  paralysis 

due  to  mitral  stenosis,  J.  A.  M.  .\.,  v.  66:   igi6,  p.  335. 
Hacker,  \'.:  Direkte  Xerveneinptlanzung  in  den  Muskel  und  muskuliire  Neurolisation  be, 

einem  Falle  von  Cucullarislahmung,  Zentalbl.  f.  Chir.,  v.  41:   1914,  No.  21,  p.  881. 
Heineke:  Die  direkte  Einpflanzung  des  Nerven  in  den  Muskel,  Zentralbl.  f.  Chir.,  v. 41: 

1914,  p.  465. 
Hoessly,  H.:  Ueber  nerven  Implantation  bei  Recurrenslahmungen,  Beitr.  z.  klin.  Chir. 

V.  99:   1916,  p.  186. 
HoRSLEV,  J.  S.:  Suture  of  the  recurrent  laryngeal  nerve.  .\nn.  Surg.,  v.  51:   igio,  p.  524. 
Suture  of  recurrent  laryngeal  nerve.  Southern  Surgical  Gynecological  Transactions,  v,  22: 

1909,  p.  161. 
MacDonald,  F.:  Transplantation  of  the  recurrent  laryngeal,  Atli.  del  XI  Congresso  Medico 

Internazionale,  v.  2:   1894,  p.  in. 
Meixzner,  R.:  Medianuslahmung  mit  folgender  I'hrenicuslahmung  nach  Schussverletzung, 

Neurol.  Centralbl.,  v.  39:   1920.  pp.  84-86. 
Ortxer,  N.:  Recurrensliihmung  bei   Mitralstenosc.  Wicn.  med.   Wchnschr.,  v.   10:   1897, 

P-  75.?- 


432  SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

PiCOT,  G.:  Le  reflexe  oculo-cardiaque  dans  les  lesions  traumatiques  incompletes  du  pneumo- 

gastrique,  Presse  Med.,  v.  27:   1919,  pp.  191-192. 
Pollock,  L.  J.:  Extracranial  injuries  of  multiple  cranial  nerves.  Arch.,  Neurol.  &  Psychiat., 

V.  4:  Nov.,  1920,  p.  517. 
Rosenthal,  J.:    Paralysis  of  the  recurrent  laryngeal  nerve  resulting  from  mitral  stenosis, 

J.  A.  M.  A.,  v.  66:  igi6,  p.  333- 
SCHMERZ,  H.:  Zur  operativen  Beeinfiussung  der  Recurrenslahmung,  Beitr.  z.  klin.  Chir., 

V.  118:  1919,  pp.  272-284. 
Schuster,  P.:  Isolierte  Lahmung  des  N.  glutseus  superior  durch  Schussverletzung,  Neurol. 

Centralbl.,  v.  34:   1915,  p.  418. 
Serafini,  J.  and  Uffraduzzi,  0.:  L'implantation  peripherique  totale  du  ncrf  laryngien 

inferieur  sur  le  pneumogastrique,  Arch,  de  Med.  exper.,  v.  28:   191S,  pp.  209-27. 
Stierlin,  R.:  Nervus  recurrens  und  Kropfoperationen,  Deutsch.  Ztschr.  f.  Chir.,  v.  89: 

1907,  p.  78. 
Symonds,   C.   p.:  a  case  of  a  lesion  of  the  suprascapular  nerve  and  first  dorsal  root,  with 

hemisection  of  the  cord  produced  by  a  single  missile,  Proc.  Roy.  Soc.  Med.,  v.  13 

Sec.  Ncur.,  1920,  p.  43. 
Vernet,  M.:  Sur  le  syndrome  du  trou  dechire  posterieur,  Paris  med,.  v.  7:  Jan.  27,  1917, 

p.  78. 
V'illaret:  Le  syndrome  de  I'espace  retroparotidien  posterieur,   Paris  med.,   v.  21:   1917, 

p.  430. 


CHAPTER  XIX 
PERIPHERAL  NERVE  TUMORS 

Neuroma. — Virchow  early  pointed  out  that  this  term  to  designate  tumors 
of  nerves  was  a  misnomer  since  in  tumors  of  nerve  trunks  neither  nerve  cells 
nor  nerA-e  libers  participate  in  the  new  growths,  and  consequently  neoplasms 
not  of  nerve  tissue  origin  cannot  be  called  neuromas.  True  neuromas  are 
found  as  hyperplasia  following  nerve  injuries,  forming  the  classical  amputation 
neuroma;  these  being  an  expression  of  an  attempt  at  regeneration  and  consist- 


FiG.  196. — Neurofibroma    of    ulnar    nerve.     Actual    size.     (Columbia    University    Pathological 

Collection.) 

ing,  in  the  main,  of  newly  formed  neuraxes,  twisted  and  intertwined,  and  Per- 
roncito  spirals.  Not  only  are  new  nerve  fibers  found  but  there  is  also  a  pro- 
liferation of  the  cells  of  Schwann  and  of  the  endoneural  connective  tissue. 
Perhaps  the  application  of  the  term  neuroma  is  not  even  here  as  accurate  as 
might  be  desired,  since  these  enlarged  nerve  ends  are  not  really  neoplasms,  but 
rather  bulbs;  the  results  of  physiological  attempts  at  regeneration. 

Fibroma. — Bruns  (1892)  has  placed  under  the  term  elephantiasis  nervorum 
a  group  of  tumors  arising  either  from  the  nerve  trunks  (multiple  fibroma) 
(see  Fig.  198)  or  from  the  terminal  branches  within  the  skin  (multiple  fibroma 
of  the  skin).     (See  Fig.   197.)     Recklinghausen  (1882)   in  a  classical  mono- 

433 

28 


434 


SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


graph  showed  the  relation  and  common  origin 
of  multiple  fibroma  of  the  skin,  fibroma  moUus- 
cum  and  multiple  neurofibroma,  both  arising 
from  the  perineurium  and  endoneurium  of  peri- 
pheral nerves;  in  the  one  instance  from  the 
terminal  twigs  within  the  skin,  and  in  the 
other  from  the  larger  nerve  trunks. 

Location. — Neurofibromas  may  occur  singly  or 
multiple  on  any  of  the  nerve  trunks  of  the  spinal, 
cranial  or  sympathetic  nerves.  They  may  be 
found  in  the  peripheral  course,  or  within  the 
cranial  cavity  (n.  acusticus,  n.  intermcdius, 
and  vagus,  etc.)  or  on  the  dorsal  roots  of  the 
spinal  nerves  within  the  spinal  canal. 

They  may  cause  clinical  manifestations  refer- 
able to  the  peripheral  distribution  of  the  nerves 
from  which  they  arise,  and  also  because  of  their 
anatomical  location  may  cause  pressure  upon 
adjacent  nerve  structures.  Those  arising  from 
the  nervus  acusticus  within  the  cranial  cavity 
give  rise  to  central  nervous  system  signs  referable 
to  the  cerebellopontile  angle,  while  others  caus- 
ing pressure  upon  the  cord  may  give  rise  to 
signs  of  spinal  cord  compression.  When  two 
or  three  nerves  lie  close  together  in  their  course 
a  tumor  of  one  may  give  rise  to  signs  referable 
to  adjacent  nerves;  for  example,  tumors  of  the 
median  nerve  in  the  middle  of  the  arm  may 
cause  pressure  upon  the  ulnar  nerve  and  give 
signs  referable  to  ulnar  distribution,  and  vice 
versa,  while  tumors  of  the  vagus  within  the 
jugular  foramen  may  cause  pressure  upon  the 
glossopharyngeal  and  spinal  accessory  nerves. 

These  peripheral  nerve  tumors  generally  lie 
within  a  definite  capsule  either  within  the  nerve 

Fig.  ic,7.-Multiple  neurofibroma  ^^^^^^^  separating  the  funiculi  and  making  them 
• — cutaneous    nerves.      (Columbia  '^  ° 

University  Pathological  Collection.)  appear   as   definite  bundles,  or  they  may  sur- 


PERIPHERAL    NERVE    TUMORS 


435 


round  the  whole  nerve  trunk  as  a  fusiform  swelling,  the  neuraxes  forming  the 
central  portion.  The  former  type,  if  well  circumscribed,  may  be  enucleated 
without  interruption  of  the  funiculi,  while  in  the  latter  complete  nerve  section 
is  necessary.  Occasionally  the  tumor  may  lie  on  one  side  resting  within  a  con- 
cavity in  the  nerve  with  all  the  funiculi  pushed  to  one  side. 

Neurolibromas  arise  from  the  endoneurium,  more  generally  perineurium, 
and  rarely  epineurium.  The  tumor  tissue  is  usually  poor  in  cells,  with  the 
fibers  closely  woven,  running  parallel  with  the  neuraxes 
and  many  times  interlacing  or  encircling  them.  AsholT 
(1913)  has  shown  that  tumors  do  not  arise  from  the 
nerve  fibers,  since  in  nerve  section  and  degeneration  of 
the  neuraxes  they  are  unaltered  and  new  tumors  even 
may  appear  after  the  neuraxes  have  degenerated.  The 
nerve  fibers,  consequently,  do  not  participate  in  the 
new  growth.  The  neuraxes  may  remain  unaltered  or 
may  undergo  degeneration  as  a  result  of  pressure. 
Degenerated  fibers  may  be  seen  adjacent  to  normal 
nerve  fibers. 

These  tumors  may  attain  relatively  large  size,  grow 
slowly  and  cause  relatively  few  signs.  (See  Fig.  198.) 
Pressure  on  adjacent  nerves  depends  on  the  location  of 
the  tumor,  its  size  and  its  consistency.  When  there 
is  room  for  displacement  of  neighboring  structures  and 
when  the  tumor  is  soft  neighborhood  signs  may  never 
occur  or  only  late.  Motor  paralysis  and  atrophy  are 
seldom  seen.  There  may  be  some  motor  weakness  but 
the  electrical  reactions  are  often  unaltered,  though  if 
measured  currents  are  used  the  strength  required  to  ob- 
tain contraction  is  increased.  IMost  often  the  patient 
complains  of  a  sensation  of  burning,  tingling,  or  other 
paraesthesias.     In  one  patient  seen  by  Dr.  Casamajor    "in^r  and  internal  cutan- 

....  .  eous     nerves.       (Columliia 

and  myself  the  prmcipal  complamt  was  a  sharji  cutting  university  Pathological 
pain  as  if  a  knife  were  being  drawn  down  the  middle  Collection.) 
of  the  fourth  finger.  (See  Figs.  199,  200,  201,  and  202.)  Neither  anesthesia 
nor  hyperaesthesia  may  be  present.  In  those  with  hyperaesthesia  the  nerve 
trunk  may  be  painful  to  pressure  over  its  course  distal  to  the  tumor.  Pain  is 
generally  the  symptom  for  which  the  patient  seeks  relief. 


Fig.  198.— Multiple 
neurofibroma  involving  the 
musculospiral,  circumflex, 
musculocutaneous,  median, 


436        SURGICAL   AND   MECHANICAL   TREATMENT    OF   PERIPHERAL   NERVES 


I 


Fig.   igg. — Neurofibroma  of  the  median  nerve.     The  tumor  is  well  circumscribed  and  the  vessels  • 
on  the  nerve  increased  in  number  and  size. 


I 


i 


Fig.  200. — Neurofibroma  of  the  median  nerve,  same  as  Fig.  199.     The  sheath  of  the  nerve  has  been 
spHt.     Note  the  separation  of  the  funiculi  by  the  tumor. 


PERIPHERAL    NERVE    TUMORS 


437 


Fig.  20I. — Stages  during  the  dissection  of  the  tumor,  same  as  Fig.   igg.     The  pedicle  of  the  tumor 
was  found  to  spread  out  and  involve  the  funiculi  above  necessitating  section  of  the  nerves. 


I  Fig.   202. — Suture   of  the  median  nerve  alter  removal  of  the  tumor  and   4    cm.    of   the    nerve. 

In  this  instance   it  was  possible  to  suture  each  funiculus  separately.     The  large  funiculus  on  the 
superlicial  surface  supplies  the  pronator  teres  and  flexor  carpi  radialis  muscles. 


438         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Treatment. — This  depends  upon  the  situation  and  the  number  of  tumors 
When  there  is  more  than  one  tumor  operation  may  not  be  feasible;  however, 
in  selected  cases  exploration  of  each  of  the  more  important  tumors  may  be 
Justifiable,  for  occasionally,  removal  may  be  possible  without  nerve  section, 
though  this  is  extremely  rare.  On  the  other  hand,  if  the  tumor  makes  up  the 
whole  of  the  nerve  trunk  with  the  funiculi  lying  within  the  tumor,  section  and 
excision  of  the  tumor  and  trunk  is  the  only  means  available.  In  single  tumors 
of    this    type  excision  and  nerve  suture  is  justifiable;  with  multiple  tumors 


Fig.  203. — Secondary  malignant  degeneration  of  neurofibroma  of  the  sciatic  nerve.     Myxosarcoma. 

multiple  excisions  with  resulting  widespread  paralyses  contraindicates  sur- 
gical procedures,  but  one  must  bear  in  mind  the  fact  that  a  certain  percentage 
of  these  tumors  undergo  malignant  degeneration  and  may  become  most  virulent 

Plexijorm  Neurofibroma  (Verneuil). — These  tumors  of  peripheral  nerves 
arise  as  simple  neurofibromas  from  the  endoneurium  and  perineurium  and 
appear  as  twisted  tortuous  masses,  resembling  in  shape  a  cirsoid  aneurysm. 
They  occur  in  the  subcutaneous  tissues,  most  frequently  in  the  region  of  the 
temples,  neck,  back  and  chest.  They  are  more  frequent  in  early  childhood 
and  are  often  hereditary.  These  tumors  hardly  fall  within  the  field  of  the 
neurosurgeon.  Their  treatment  consists  in  excision  when  possible,  together 
with  the  overlying  skin.  Plexiform  neurofibromas  have  been  described  in 
the  larger  nerve  trunks  and  in  these  the  treatment  is  similar  to  that 
described  for  single  neurofibroma. 

Malignant  Degeneration. — Garre  (1892)  has  pointed  out  that  in  the  cases 


PERIPHERAL    NERVE    TUMORS  43Q 

of  neurofibromas  collected  by  him,  malignant  degeneration  occurred  in  about 
i2'^"(.  Courvoisier  (1886)  found  fifty-three  cases  of  sarcomatous  degeneration 
in  eight  hundred  neurofibromas.  Of  these  fifteen  were  pure  sarcoma;  the 
remaining  being  myxosarcoma  and  fibrosarcoma  .     (Sec  Fig.   203.) 

When  malignant  change  occurs  the  virulence  and  the  \-ehemence  with 
which  recurrence  takes  place  is  amazing  (Garre).  The  majority  show  a  local  or 
regional  recurrence  within  a  year;  in  others  this  may  be  delayed  for  a  number  of 
years.  Volkmann  operated  on  one  case  several  times  and  finally  at  the  end  of 
ten  years  amputation  became  necessary,  while  in  another  case  recurrence 
occurred  only  after  six  years.  Garre  has  called  attention  to  the  fact  that  in 
secondary  malignant  neuroma  metastases  occurs  regionally;  that  is,  within  the 
vicinity  of  the  primary  tumor,  within  the  same  nerve  or  adjacent  nerves,  and 
only  late  are  more  remote  metastases  found.  The  opposite  occurs  in  primary 
sarcoma  with  remote  metastases  early  and  not  regional. 

Clinically  it  is  difficult  to  distinguish  between  simple  neurofibroma  and 
those  in  which  malignant  change  has  occurred.  Within  the  same  tumor,  areas 
of  malignant  change  are  found  adjacent  to  simple  neurofibromatous  tissue. 
However,  when  a  slowly  growing  neurofibroma  with  few  symptoms  shows  rapid 
increase  in  growth,  together  with  increasing  signs,  such  as  paraesthesias,  hyper- 
aesthesias  or  motor  changes,  malignant  degeneration  is  to  be  suspected.  When 
sarcomatous  change  has  occurred,  the  tumor  may  break  through  its  capsule 
and  invade  the  funiculi  and  the  surrounding  tissues  with  increasing  signs 
of  nerve  involvement  due  to  the  increased  pressure  and  damage  to  the 
neuraxes. 

Genesis. — von  Recklinghausen,  Garre  (1892),  Ribbert  (1904)  and  others 
believe  that  this  entire  group  of  nerve  tumors  described  under  the  term  of  ele- 
phantiasis nervorum  and  including  neurofibroma,  plexiform  neuroma,  secondary 
malignant  neuroma  and  fibroma  moUuscum  represent  "a  congenital  affection 
with  a  congenital  predisposition  to  the  formation  of  connective  tissue  tumors 
of  the  nerves,  perhaps  due  to  some  irregular  distribution  and  arrangement  of 
the  connective  tissue  elements  of  the  nerves  permitting  of  independent  growth." 
This  congenital  predisposition  is  further  suggested  by  the  appearance  of  such 
tumors  in  early  childhood,  their  multiplicity  and  the  hereditary  tendency. 
Garre  believes  that  "in  the  tendency  to  sarcomatous  degeneration  in  neuro- 
fibromas of  elephantiasis  neuromatoides  congenita  trauma  plays  perhaps  a 
slight  role  in  initiating  the  secondary  malignant  change,  serving  merely  to 
quicken  the  inherent  malignant  tendency  already  present." 


440         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Primary  Neurosarcoma. — Such  tumors  may  occur  in  any  of  the  nerves  in 
which  neurofibromas  are  found.  They  arise  from  the  endoneurium,  perineu- 
rium or  cpineurium,  and  may  be  spindle-cell  variety,  fibro-  or  myxosarcoma. 
The  nerve  tissue  does  not  participate  in  the  growth  of  the  tumor,  but  may  be 
seen  in  the  tumor  as  normal  nerve  fibers  or  in  various  stages  of  degeneration. 
This  arrangement  has  been  splendidly  shown  by  numerous  investigators. 
Bloodgood's  (1909)  report  of  Mackenzine's  case  is  an  excellent  example  where 
normal  nerve  fibers  were  found  together  with  areas  of  nerve  degeneration. 
Within  the  tumor  proper  there  was  no  gross  or  microscopical  evidence  of  nerve 
fibers,  though  in  some  parts  of  the  nerve  the  tumor  cells  had  invaded  the 
nerve  fibers,  destroying  them  and  replacing  the  endoneurium  with  tumor  cells. 
Early  motor  and  sensory  signs  of  nerve  involvement  in  these  neoplasms  are 
met  with  due  to  the  rapid  invasion  and  destruction  of  the  nerve  fibers. 

These  tumors  may  attain  relatively  large  size.  In  Mackenzie's  case 
12  inches  of  nerve  was  excised  from  the  sciatic  and  in  Bobrov's  (1895)  case 
a  tumor  of  similar  size  was  excised  also  from  the  sciatic  nerve.  Both  of  these 
patients  were  alive  five  years  after  the  original  operation,  and  in  neither  was 
there  any  evidence  of  recurrence. 

Metastases  in  primary  sarcoma  of  the  nerves  generally  do  not  occur  as 
regional  metastases  in  the  same  or  adjacent  nerves,  but  more  remotely,  in  the 
lungs  and  pleura,  etc. 

Treatment. — Early  diagnosis  should  be  made  and  followed  by  immediate 
operation  with  wide  excision  of  the  tumor,  cutting  well  into  sound  nerve  both 
distally  and  proximally.  Considerations  of  closure  of  the  resulting  defect  are 
matters  of  secondary  moment  to  be  decided  after  complete  excision  of  the  tumor. 
In  early  sarcoma  or  in  fibroma  in  which  secondary  malignant  change  has  occurred 
it  is  often  difficult  to  determine  at  operation  whether  or  not  one  is  dealing  with  a 
fibroma,  since  in  both,  malignant  and  simple  fibromatous  tissue  are  intermingled. 
Generally  the  sarcomas  whether  primary  or  secondary,  are  more  vascular  and 
bleed  more  readily  and  are  less  circumscribed. 

Neuroblastoma. — ^In  recent  years  attention  has  been  called  to  certain 
tumors  of  peripheral  nerves  in  which  the  cell  type  is  the  neurolemma  cell. 
This  was  first  suggested  by  Verecay  (1908),  and  later  by  Stout  (1918).  Verecay 
described  multiple  tumors  of  peripheral  nerves  in  which  he  believed  there  was 
a  marked  proliferation  of  the  neurolemma  cells.  Stout's  case  showed  a  large 
tumor  of  the  ulnar  nerve  with  an  ulcerating  surface,  and  numerous  metastases 
in  the  entire  upper  extremity.     Histological  examination  of  the  tumor  showed 


PERIPHERAL    NERVE    TUMORS 


441 


"masses  and  strands  of  rather  small,  rounded  cells,  many  of  which  showed 
mitoses,  separated  by  trabecuLx  of  connective  tissue.  Scattered  through  the 
tumor  eclls  at  irregular  intervals  are  many  rosettes.  .  .  .  These  were  small 
circular  holes  surrounded  by  a  sharply  outlined  membrane  which  is  red  with 
Mallory  stain."     Stout  concluded  "that  the  tumor  was  a  malignant  neoplasm 


Fig.  204. — Microphotograph  of  section  of  tumor  of  the  ulnar  nerve  taken  just  below  the  interna  1 
epicondyle  of  the  humerus.     .4,  Bundle  of  nerve  fibers  in  its  connective  tissue  capsule;  P,  perineurium 
is  shown  with  a  mass  of  tumor  cells,  T,  sharing  the  space  and  in  intimate  relationship  with  the  nerve 
fibers,  F.     Note  large  size  and  hyperplasia  of  the  neurolemma  cells.     (Stout,  Presbyterian  Hospital 
i     Report.     Xew  York  City,  1918.; 

which  grossly  resembled  the  sarcomas,  and  that  since  the  neurolemma  cells  of 
peripheral  nerve  are  probably  homologous  to  the  neuroglia  of  the  central 
nervous  system,  this  type  of  tumor  may  arise  from  the  neurolemma  cells  or 
lemmocytes."     (See  Figs.  204,  205,  206.) 

This  type  of  tumor  described  by  Verecay  and  Stout,  as  has  been  said,  is 
comparable  to  the  glioma  of  the  central  nervous  system,  since  the  neurolemma 
cells  of  the  peripheral  nerves  are  homologus  with  the  neuroglia.     It  has  already 


442 


SURGICAL   AND   MECHANICAL   TREATMENT   OF    PERIPHERAL   NERVES 


been  pointed  out  (see  p.  26)  that  the  neurolemma  cells  are  ectodermal  cells  which 
migrate  from  the  neural  crest  and  neural  tube  along  with  the  developing  nerve 
fibers.  Hence,  the  possibility  of  two  different  types  of  tumors  in  the  peripheral 
as  in  the  central  nervous  system — the  sarcoma  of  mesodermal  origin  and  the 
neuroblastoma  of  ectodermal  origin. 

Leprosy. — While  leprosy  cannot  be  classed  under  tumors,  nodular^enlarge- 
ments  of  peripheral  nerves,  especially  the  ulnar,  may  occur  in  leprosy.     The 


Fig.  205. — Mallory  stain — neuroblastoma;  section  through  tumor  of  ulnar  nerve  showing  rosettes,  R, 
and  connective  tissue  trabeculae,  C.    (Stout,  Presbyterian  Hospital  Report,  New  York  City,  igi8.) 

possibility  of  this  condition  must  be  considered  when  motor  signs,  atypical 
sensory  changes  without  pain,  and  skin  changes  are  found  with  a  nodular 
enlargement  of  the  nerve  trunk.  If  a  thorough  examination  is  made  changes 
in  the  te.xture  and  thickness  of  the  skin  will  be  found  which  do  not  correspond 
exactly  with  the  cutaneous  distribution  of  the  nerve  and  are  not  met  with  in  any 
other  nerve  lesion.  A  patient  having  an  old  fracture  of  the  radius  and  ulna  was 
presented  for  ulnar  nerve  operation;  but  on  account  of  the  atypical  sensory 
findings  and  the  peculiar  skin  changes  the  diagnosis  of  leprosy  was  made. ; 


PERIPHERAL    NERVE    TUMORS 


443 


It  was  afterwards  found  that  the  patient  was  a  native  of  Haiti.  In  some 
instances  a  localized  nodular  enlargement  may  Ix'  found  on  a  nerve  with  typical 
motor  and  sensory  changes  referable  to  the  nerve  involved,  but  no  other  sensory 
or  skin  changes,  and  the  diagnosis  of  leprosy  is  not  made  until  operation.  If 
the  lesion  is  well  localized  excision  and  suture  are  indicated. 


Fig.  206. — .Same  as  Fig.  205.  Mallory  stain — higli  power  microphotograph  of  three  rosettes, 
R,  showing  deeply  stained  membrane  or  rim  from  wliich  radiate  the  tine  fibrils  between  the  sur- 
rounding cells;  C,  trabecula  of  connective  tissue.  (Stout,  Presbyterian  Hospital  Report,  New  York 
City,  1918.) 


REFERENCES 

Adrian,  C:  Ueber  Neurofibromotose  und  ihre  Koniplication,  Beitr.  z.  klin.  Chir.,  v.  31, 

1901,  p.  I. 
AsCHOFF,  L.:  Pathologische  Anatomic,  3d  edit.,  Gustav  Fischer,  Jena,  1913,  v.  2. 
AuERBACH,  S.  and   Brodnitz:   Neurofibrom    des  N.  ulnaris  am  Oberarm;  Extirpation; 

Heilung,  Mitt.  a.  d.  Grenzgeb.  d.  Med.  u  Chir.,  v.  21:  1910,  p.  589. 
Bloodgood:  See  Mackenzie:  Resection  of  the  sciatic  nerve,  Ann.  Surg.,  v.  i:  1909,  p.  295. 
BoBROV:  The  removal  of  sciatic  nerve  over  an  extent  of  12  centimeters,  Khirurgicheskaya 

Lietopis,  Moscow,  v.  5:  1895,  p.  578. 


444         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Bruns,  p.:  Ueber  das  Rankenneurom,  Beitr.  z.  klin.  Chir.,  v.  8:  1892,  p.  i. 
CouRVOisiER,  L.  G.:  Die  Neurome:  Eine  klinische  Monographie,  Basel,  Benno  Schwalbe, 

1886. 
Garre,  C.:  Ueber  Sekundiir  Maligne  Neurome,  Beitr.  z.  klin.  Chir.,  v.  g:  1892,  p.  465. 
GoLDMANN,  E.:  Beitrag  zu  der  Lehre  von  den  Neuromen,  Beitr.  z.  klin.  Chir.,  v.  10:  1893, 

P-  13- 
Ueber  das  Fehlen  von  Funktionsstoerungen  nach  der  Resektion  von  peripheren  Nerven, 

Beitr.  z.  klin.  Chir.,  v.  51:   1906,  p.  183. 
KN.A.USS,   K.:  Zur   Kenntniss   der  achten   Neurome,  Neuroma  verum  multiplex  amyehni- 

cum  gangliosum,  Virchow's  Arch.  f.  path.  Anat.,  v.  153:  1898,  p.  29. 
McArthur,  L.  L.:  Sarcoma  of  the  posterior  tibial  nerve;  excision;  removal  of  metastatic 

focci  in  retroperitoneal  lymph  glands  three  months  later,  Surg.  Clin.  Chic,  v.  4:  1920, 

p.  131. 
Mackenzie:  Resection  of  the  sciatic  nerve,  Ann.  Surg.,  v.  i :  1909,  p.  295. 
v.  Recklinghausen,  F.:  Ueber  die  Multiplen  Fibrome  der  Haut  und  ihre  Beziehung  zu  den 

IMultiplen  Neuromen,  Festschrift  zu  Rudolf  Virchow,  Berlin,  A.  Hirschwald,  1882. 
Ribbert,  H.:  Geschwulstlehre  ftir  Arzte  und  Studierende,  F.  Cohen,  Bonn,  1914. 
Stout,  A.  P.:  A  tumor  of  the  ulnar  nerve,  Med.  and  Surg.  Report  Presbyterian  Hosp., 

New  York,  v.  10:  Oct.,  1918,  p.  236. 
Veeecay,  J.:  Multiple  Geschwuldste  als  Systemerkrankung  am  nervorem  Apparate,  Fest- 
schrift f.  Chiari,  Prag.,  1908,  p.  378. 
Wright,  J.  H.:  Neurocytoma  and  neuroblastoma;  a  kind  of  tumor  not  generally  recognized, 

J.  Exper.  M.,  v.  12:  1910,  p.  556. 


CHAPTER  XX 
CAUSALGIA 

Sicard  (1916)  was  the  first  to  recommend  alcohol  injection  of  the  nerve 
trunk  in  the  treatment  of  causalgia.  His  suggestion  was  based  upon  work 
which  he  had  done  previously  with  Brissaud  and  Tanon  (1906),  in  the  alco- 
holization of  the  facial  nerve  for  facial  spasm  and  tic.  Two  years  earlier 
Schlosser  (1904)  in  ^Munich  had  attempted  to  inject  alcohol  in  the  region  of  the 
facial  nerve  at  the  stylomastoid  foramen.  Pitres  and  Vaillard  (1887)  tried  to 
prove  that  peripheral  nerves  were  susceptible  to  the  action  of  chemical  sub- 
stances, though  they  were  more  resistant  than  the  surrounding  tissues.  They 
injected  a  series  of  substances  in  the  neighborhood  of  different  nerves,  among 
them  alcohol  and  ether,  which  previously  had  been  used  by  Salvat  (1889)  and 
others. 

Pitres  and  Vaillard  found  that  by  injecting  ether  in  the  region  of  the 
sciatic  nerve  in  the  guinea  pig  complete  motor  and  sensory  paralysis  ensued 
below  the  site  of  injection,  both  anesthesia  and  paralysis  appearing  immediately 
after  the  injection.  Histological  examination  showed  that  at  the  level  of  the 
injection  and  below  this  point  the  nerve  had  undergone  typical  Wallerian 
degeneration,  while  above  the  level  of  injection  no  changes  were  found  in  the 
nerve.  These  authors  conclude  that  injection  of  ether  in  the  neighborhood 
of  nerve  trunks,  by  provoking  local  degeneration  equivalent  to  physiological 
section  of  the  nerve,  might  be  applicable  to  the  treatment  of  those  clinical 
conditions  in  which  nerve  stretching  or  nerve  section  had  been  employed  to 
advantage. 

According  to  Sicard,  60%  alcohol  does  not  act  on  motor  but  only  on  sen- 
sory neuraxes,  producing  anesthesia,  not  paralysis.  Sicard  reported  twenty- 
one  cases  of  nerve  irritation  treated  by  alcohol  injection — six  median,  three 
median  and  ulnar,  five  sciatic,  five  brachial  plexuses,  and  two  amputation 
neuromas.  To  these,  he  added  nine  patients  treated  by  Pitres — seven  median 
and  two  sciatic;  those  treated  by  Grinda  (1916) — one  sciatic  and  one 
median,  and  seven  by  Godelewski  (1916),  all  of  whom  were  relieved  following 
injections  of  60%  alcohol.  Godelewski  also  injected,  with  immediate  relief, 
an  amputation  neuroma  which  had  remained  painful  in  spite  of  two  operations. 

445 


446         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

Sicard  recommended  injection  of   approximately  3  cc.  of  60%  alcohol, 
using  a  very  fine  needle,  and  to  make  sure  that  the  injection  reaches  all  the 


Fig.  207. — Involvement  of  the  median  nerve  in  a  delicate  veil  of  scar  in  a  patient  with  median     ^ 
nerve  causalgia.     Pain  relieved  by  liberation. 

funiculi,  he  inserts  the  needle  in  several  places  in  the  nerve  trunk.     It  is  most 
important  that  the  injection  should  be  made  at  least  3  or  4  cm.  above  the    • 


CAUSALGIA  447 

lesion,  thus  reaching  all  collateral  branches  of  the  neuraxes  in  the  region  immedi- 
ately above,  for  these  might  also  carry  painful  impulses.  In  several  cases  in 
which  the  injection  was  not  carried  above  the  lesion,  but  within  or  below  the 
lesion,  no  relief  was  obtained  because  these  collaterals  remained  intact. 

He  advises  sterilization  of  the  alcohol  in  sealed  glass  tubes  in  order  to 
conserve  its  proper  strength.  However,  this  seems  hardly  necessary  since 
60%  alcohol  is  already  bactericidal. 

In  cases  of  causalgia  of  longer  duration,  injection  of  80%  alcohol  is  advised. 
Before  injection,  the  nerve  should  be  freed  from  all  surrounding  scar 
tissue  (see  Figs.  207  and  20S)  and  the  field  reconstructed  so  that  the  nerve  may 
lie  in  as  smooth  a  bed  as  possible. 

Since  Sicard's  report,  numerous  others  have  used  the  method  with  success, 
particularly  Pitres  and  Marchand  (1916).  The  latter  have  tried  alcohol 
I  injections,  above  the  site  of  the  nerve  lesion  according  to  the  method  of  Sicard, 
I  in  more  than  thirty  cases,  and  so  far  with  complete  success.  They  showed 
that  following  injection  of  60%  alcohol  into  the  nerve  trunk,  motor  function 
may  persist  even  though  complete  reaction  of  degeneration  is  present.  Thus 
in  one  case  of  injection  of  the  sciatic  for  causalgia  with  all  movements  of  the 
leg  preserved,  the  causalgia  disappeared  following  injection  while  voluntary 
motion  was  unimpaired. 

Pitres  and  Marchand  further  conclude  that  alcohol  injection  does  not 
accentuate  an  already  existing  paralysis  nor  cause  additional  paralyses.  In 
j  one  case  of  injury  to  the  median  in  the  arm,  injection  was  done  not  above  the 
lesion  but  below,  and  here  the  relief  was  but  transient.  In  causalgia  of  the 
I  median  nerve  with  an  associated  paralysis,  as  for  example  that  of  the  musculo- 
I  spiral  and  the  ulnar  nerve,  the  relief  from  severe  pain  of  causalgia  dissipated 
I  the  apparent  paralysis  of  the  other  two  nerves,  which  had  been  merely  protec- 
;  tive.  These  authors  are  convinced  of  the  value  of  alcoholization  of  the  nerve 
'  trunk  in  causalgia. 

I  Meige  and  Athanassio-Benisty   (1916)    have  laid   special  stress   on   the 

[  probable  role  of  the  sympathetic  in  causalgia.  According  to  them  it  is  only 
i  by  a  lesion  of  the  sympathetic  that  the  widely  variant  symptoms  found  may  be 
1  explained.  The  synipathetic  may  be  involved  either  on  the  great  vessels 
such  as  the  brachial  artery,  or  on  the  small  vessels  which  run  within  the  nerve, 
I  particularly  the  median  and  the  sciatic,  or  the  sympathetic  fibers  within 
I  the  nerve  trunk  itself.  Either  of  these  two  sympathetic  systems,  or  both,  may 
be  involved.      If  the  sympathetic  is  implicated  within  the  nerve,  then  the 


448         SURGICAL    AND    MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 


Ulnar  N. 


Fig.  208. — Involvement  of  the  median  nerve  and  brachial  artery  in  scar  in  a  patient  with  1 
causalgia  of  the  median  nerve.     No  motor  signs  were  present.     Pain  relieved  by  liberation  of  the 
median  nerve  with  injection  of  alcohol  into  the  nerve  above  the  lesion. 


CAUSALGIA  449 

pain  corresponds  more  exactly  to  the  peripheral  distribution  of  the  injured 
nerve. 

In  certain  cases  in  which  it  appeared  that  the  perivascular  sympathetic 
was  injured,  Leriche  (191 7)  attempted  removal  of  the  sympathetic  along  the 
great  vessels  in  the  region  of  the  injury  for  a  distance  of  8  to  10  cm.  In  these 
instances  marked  diminution  in  the  size  of  the  vessel  occurs,  decreasing  its 
normal  caliber  to  one-fourth;  the  pulse  is  barely  felt  and  the  blood-pressure  is 
lowered,  but  is  followed  in  two  or  three  hours  after  operation  by  a  local  rise  in 
temperature  with  increase  in  the  size  and  volume  of  the  pulse,  as  well  as  a  local 
rise  in  blood-pressure,  which  persists  from  two  to  four  weeks.  Changes  in  the 
motor  and  vasomotor  condition  of  the  extremity  are  strikingly  seen  in  paralyses 
and  contractures  of  reflex  origin,  as  described  by  Babinski  and  Froment  (191 7), 
when  perivascular  sympathectomy  is  done.  A  certain  amount  of  motion 
returns  almost  immediately  and  usually  coincident  with  this,  evidences  of  local 
vasodilatation  are  seen. 

Leriche  believed  that  voluntary  mo\ement  is  in  a  certain  sense  dependent 
upon  the  sympathetic  system.  Integrity  of  the  somatic  efferent  nerve  and 
muscle  alone  does  not  complete  all  factors  involved  in  muscular  innervation, 
hut  equally  essential  is  the  integrity  of  the  postganglionic  sympathetic  fiber. 
When  the  sympathetic  is  implicated,  the  muscles  may  become  hardened  and 
undergo  contracture.  Relaxation  and  contraction  of  these  muscles  is  impossible 
by  voluntary  efYort.  Perivascular  sympathectomy  may  remove  this  inhibition 
and  permit  progressive  improvement  of  voluntary  motion.  In  eighteen  cases 
of  this  type  operated,  eleven  were  improved,  two  cured,  with  two  failures  and 
with  two  recurrences.  Thus  in  sixteen  operations  improvement  with  some 
return  of  voluntary  movement  and  disappearance  of  contractures  occurred  in  all 
very  soon  after  operation  and  lasted  as  long  as  vasodilatation  was  present,  but 
with  diminution  of  vasodilatation  a  decrease  in  movements  again  occurred. 

Following  operation,  Leriche  supplements  measures  intended  to  increase 
the  circulation,  such  as  hot  baths  in  parafEne  heated  to  sixty  degrees,  contrast 
baths,  massage  and  re-education  of  the  muscles. 

The  painful  phenomena  in  causalgia  Leriche  also  considers  are  due  to 
alterations  in  the  perivascular  sympathetic  or  the  intraneural  sympathetic 
a  part  of  which  may  be  brought  to  the  nerve  through  the  special  artery 
supplying  the  nerve.  Marie  and  Athanassio-Benisty  have  pointed  out  that  the 
median  and  the  sciatic  nerves  have  a  special  blood  supply  and  that  these 
nerves  also  lie  near  great  vessels  on  which  there  is  a  rich  sympathetic  supply. 


450        SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 

Since  Leriche's  work,  numerous  attempts  have  been  made  by  perivascular 
sympathectomy  to  relieve  reflex  contractures  and  the  painful  phenomena  in 
causalgia,  with  more  or  less  transient  success.     In  those  cases  in  which  at  opera- 

Brcvchial  A.  contracted 


\ 


Fig.  2og. — Perivascular  sympathectomy  in  a  patient  with  synesthesialgia  and  ulnar  nerve 
injury.  Xote  that  the  brachial  artery  is  contracted  to  about  one-fourth  its  normal  size.  The  inserts 
A  and  B  show  the  perivascular  sympathetic  being  stripped.  Blunt  dissectors  and  fine  iris  scissors 
are  used. 

tion  scar  is  found  to  include  the  median  nerve  and  in  which  there  is  thought 
to  be  involvement  of  the  perivascular  sympathetic,  as  evidenced  by  the  decrease 
in  the  caliber  of  the  brachial  artery — previous  ligation  or  occlusion  of  the  vessel 
having  been  excluded — the  perivascular  sympathetic  may  be  stripped  and  the 
median  freed;  but  also  injection  of  alcohol  into  the  median  should  be  done  as 
well.  In  two  cases  of  mine,  alcohol  was  not  injected  into  the  median,  the  latter 
was  freed,  and  the  perivascular  sympathetic  removed  from  the  brachial.     Fol- 


CAUSALGIA  45 1 

lowing  it  some  amelioration  of  the  symptoms  occurred,  but  improvement  was 
not  complete  until  alcohol  was  injected  into  the  nerve. 

In  performing  perivascular  sympathectomy,  fine  blunt-pointed  iris  scissors 
and  broad-pointed  anatomical  forceps  should  be  used  to  tear  off  the  layer  of 
loose  connective  tissue  which  surrounds  the  vessel  wall  and  in  which  the  sympa- 
thetic fibers  lie.  (See  Fig.  209.)  When  the  line  of  cleavage  is  once  established 
there  is  relatively  little  difficulty,  providing  care  is  taken  to  maintain  the  sepa- 
ration along  the  proper  layer.  The  tissue  should  be  stripped  from  above  down, 
for  in  this  manner  the  small  blood  vessels  are  more  readily  recognized  and  are 
laid  bare  with  less  danger  of  being  torn  at  their  origin  before  it  is  realized  that 
they  are  included  in  the  tissue  which  is  being  removed. 

Recently  ^'eillert  (1918)  attempted  perivascular  sympathectomy  in  a  case 
of  Raynaud's  disease,  in  which  he  stripped  off  the  sympathetic  from  the  brachial 
artery  on  one  side  and  noted  amelioration  not  only  on  the  side  of  operation, 
but  also  in  the  opposite  extremity.  This  he  believed  to  be  an  indication  of  the 
purely  sympathetic  affect  in  this  disease  and  also  of  the  metamerization  of  the 
functional  association  characteristic  of  the  sympathetic  system. 

The  value  of  perivascular  sympathectomy  may  be  questioned  in  view  of  the 
work  of  Kramer  and  Todd  (1914),  and  Potts  (1914)  showing  that  the  sympa- 
thetic supply  of  the  vessels  of  the  extremities,  with  the  exception  of  the  sub- 
clavian, is  not  through  a  continuous  perivascular  sympathetic  system,  but 
through  the  adjacent  nerves  which  distribute  sympathetic  branches  to  the 
vessels  at  various  intervals  along  their  course.  (See  Figs.  210,  211.)  Branches 
are  given  off  more  frequently  to  the  more  peripheral  portions  of  the  vessels, 
probably  because,  as  Kramer  thought,  the  diminishing  caliber  of  the  vessel 
required  greater  vasomotor  regulation.  The  vessels  receive  sympathetic 
fibers  from  the  same  nerves  as  supply  the  adjacent  parts. 

The  nerve  supply  to  the  posterior  tibial,  peroneal  and  plantar  arteries,  as 
given  by  Potts,  explains  on  an  anatomical  basis  causalgia  in  sciatic  nerve  injuries 
involving  the  tibial  division.  The  vascular  nerve  supply  in  the  dorsum  of  the 
leg  and  the  sole  of  the  foot  is  through  the  tibial  nerve  and  its  branches.  (See  Figs. 
212  and  213.)  However,  the  explanation  of  causalgia  in  injuries  of  the  median 
nerve  is  more  difficult  to  understand  since  the  vascular  nerve  fibers  for  the  ves- 
sels of  the  upper  extremity,  as  given  by  Kramer  and  Todd,  are  largely  through 
the  musculocutaneous,  ulnar  and  radial  nerves.  However,  the  median  nerve 
supplies  branches  to  the  superficial  palmar  arch  of  the  thumb,  index  and 
middle  fingers;  the  vessels  of  the  fourth  and  fifth  fingers  are  supplied  by  the 


452    SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERLPHERAL  NERVES 


ULNAR 
NERVE 

ULNAR 

ARTERY 


MEDIAN 
NERVE 


RADIAL 
-      NERVE 
/(superficial 
ramus' 


RADIAL 
ARTERY 


Fig.  2IO. — Diagram  to  illustrate  the  nerve  supply  to  the  radial  and  ulnar  arteries  and  to  the 
superficial  volar  arch.  The  radial  artery,  though  sometimes  receiving  a  branch  from  the  musculo- 
cutaneous nerve,  obtains  branches  from  the  superficial  terminal  ramus  of  the  radial  nerve.  The 
ulnar  nerve  suppHes  its  companion  artery  by  twigs  from  its  main  trunk  and  from  its  palmar  cutaneous 
branch.  The  complicated  supply  from  median  and  ulnar  nerves  to  the  superficial  volar  arch  and 
digital  vessels  is  also  shown.     (Kramer  and  Todd,  Anatomical  Record,  19 14.) 


ULNAR  NERVE 
ULNAR  ARTERY 


ULNAR  NERVE 
deep  ramus  I 

DEEP  VOLAR 
ARCH 


Fig.  in. — Diagram   of   the   branches   of   the    ramus    profundus   of  the  ulnar  nerve  to  the  deep' 
volar  arch.     (Kramer  and  Todd,  .Vnatomical  Record,  1914.) 


CAUSALGIA 


453 


/ 


A   glutaea  inferior_ 
N.  glutaeus  inferior- 


Muscular  artery 


-Azygos  Nerve 
Nerve  to  M.  popUteus 


_  Nerve  to  M.  flexor 
longus  hallucis 


Fig.  212. — Distribution  of  nerves  to  tlie  inferior  gluteal,  popliteal,  posterior  tibial  and  peroneal 
arteries.  Note  the  large  twig  received  by  the  posterior  tibial  artery  immediately  above  the  medial 
malleolus.     Twigs  marked  V  are  distributed  to  vena;  comites.     (Potts,  Anat.  Anzeig.,  1914-15.) 


Fig.  213. — Distribution  of  nerves  to  the  medial  and  lateral  plantar  arteries  and  their  branches. 

(Potts,  Anat.  Anzeig.,  1914-15.) 


454    SURGICAL  AND  MECHANICAL  TREATMENT  OF  PERIPHERAL  NERVES 

ulnar  nerve.  If  other  investigations  should  support  this  limited  vascular  supply 
through  the  median  nerve  it  would  be  difficult  to  account  for  the  extensive  vas- 
cular changes  noted  in  incomplete  lesions  of  this  nerve. 

Since  the  vascular  nerve  supply  reaches  the  vessels  of  the  extremity  at 
various  intervals,  localized  perivascular  sympathectomy  over  an  area  of  lo 
to  12  cm.  as  recommended  by  Leriche  would  suffice  for  only  approximately 
the  area  of  vessel  denuded,  since  below,  at  various  intervals,  intact  sympa- 
thetic fibers  are  received  from  adjacent  nerves.  On  the  other  hand,  extensive 
vascular  lesions  remote  from  the  site  of  the  injury  may  be  explained  by  involve- 
ment of  the  sympathetic  fibers  in  the  main  nerve  trunk,  since  it  has  been 
shown  that  these  fibers  reach  the  vessels  not  through  a  continuous  perivascular 
system  of  libers  but  intermittently  through  the  adjacent  nerve  trunks.  Stop- 
ford  (191S)  has  shown  that  extensive  changes  in  the  vessel  walls  may  result 
from  irritative  nerve  lesions  without  direct  injury  to  the  vessel  wall  producing 
an  extensive  endarteritis  over  a  considerable  distance. 

In  view  of  such  findings  it  must  be  considered  that  perivascular  sympathec- 
tomy is  not  as  yet  on  a  sound  anatomical  or  clinical  basis;  however,  in  view  of 
Leriche's  experience  the  method  should  not  be  condemned  until  further  clinical 
evidence  is  gained. 

Lortat  and  Hallez  (1918)  in  a  case  of  median  and  ulnar  paralysis, 
with  section  of  the  brachial  artery,  ligated  the  median  nerve  with  catgut  and 
found,  subsequently,  complete  cessation  of  pain,  vasomotor  and  secretory  dis- 
turbances. While  this  method  may  have  advantages  in  certain  cases  the  author 
has  had  no  experience  with  its  use. 

Causalgia  may  not  be  the  only  form  of  pain  demanding  operative  inter- 
ference. Nerves  caught  in  scar  or  callus  may  give  definite  signs  of  irritation  with 
areas  of  exquisite  hyperesthesia.  Minute  foreign  bodies  in  the  nerve  may  cause 
painful  symptoms  referable  to  only  part  of  the  nerve  distribution — dissociated 
hyperesthesia.  In  such  conditions  operative  measures  are  indicated  to  relieve 
pain  even  without  motor  disturbances  being  present. 


REFERENCES 

Barth,  H.:  Les  injections  sous-cutanees  d'ether  dans  le  traitement  de  la  pneumonic 
adynamique,  Gaz.  hebdom.  series  2,  v.  18:  1S81,  pp.  Soi,  816,  839. 

Bidder,  F.:  Versuche  iiber  die  Moglichkeit  des  Zusammenheilens  functional  vershiedener 
Nervenfasern,  MuUer's  Archiv.,  1S42,  p.  102. 


CAUSALGIA  455 

Brissaud,  Sicard,  and  Tanox:  Essais  de  Iraitement  de  certain  cas.    .    .  par  I'alcoolisation 

locale  des  troncs  nerveux,  Rev.  neurol.,  v.  14:  1006,  p.  633.     Also  in:  Bull,  et  mem.  Soc. 

med.  d.  hop.  de  Par.,  v.  23:  1906,  p.  831. 
Dangers  des  injections  d'alcool  dans  le  nerf  sciatique,  Rev.  neurol.,  v.  15:  1907,  p.  633. 
Leriche,   R.:  De  la  sympathectomie  peri-arterielle  et   de  ses  resultats,  Presse  Medicale, 

V.  25:  Sept.  10,  1917,  p.  513. 
LoRTAT,  J.  and  Giron,  E.:  Guerison  rapide  de  la  douleur  dans  la  "causalgie"  du  median 

avec  troubles  paralytiques  graves  par  la  ligature  du  nerf  avec  catgut,  Paris  med.,  v.  8: 

1918,  p.  493. 
LoRTAT,  J.  and  Hallez,  G.:  Traitement  de  la  causalgie  du  median  avec  trouble  paralytique 

grave  par  la  ligature  du  nerf  au  catgut,  Bull,  et  mem.  Soc.  med.  d.  hop.  de  Paris, 

Series  3,  v.  42:  1918,  p.  239. 
Marie,  P.  and  Athanasio-Benisty:  Forme  douloureuse  des  blessures  du  nerf  median 

Presse  med.  v.,  18:  March,  1915. 
Les  signes  cliniques   des  lesions   de   I'appareil  sympathique   et  de  I'appareil  vasculaire 

dans  les  blessures  des  membres,  Presse  med.,  v.  24:  i,   1916,  p.  153. 
Mitchell,  S.  W.,  Morehouse,  G.  R.  and  Keen,  W.  W.:  Gunshot  wounds  and  other  injuries 

of  nerves,  Phila.  J.  B.  Lippincott  Co.,  1864. 
Perthes:  Ischiadikusresektion  wegen   Schussneuritis  (Medizin-Naturwissenschafll.  Verin 

Tiibingen,  15  Jan.,  1917),  Miinchen.  med.  Wchnschr.,  v.  64:  1917,  p.  920. 
Pitres,  a.  and  Vaillard,L.:  Action  de  I'alcool  sur  les  troncs  nerveux,  Soc.  de  Biologic,  serie 

3,  v.  4:    April  9  and  May,  14,  1887,  p.  228,  p.  299. 
Nevrites  peripheriques  experimentalement  provoquees  par  des  injections  hypodermiques 

de  diverses  substances,  Compt.  rend.,  Soc.  de  Biologie,  series  8,  v.  4:  1887,  pp.  228-299 
Potts,  L.  W.:  The  distribution  of  nerves  to  the  arteries  of  the  leg,  Anat.  Anz.,  v.  47:  1914, 

p.  138. 
Salvat,  A.  F.:  Etude  sur  les  nevrites  consecutives  aux  injections  hypodermiques  d'ether, 

Th.  Doct.  Bordeaux,  1884. 
ScHLOSSER:  Berl.  klin.  Wchnschr.,  1904. 
Sicard,  J.  A.:  Traitement  des  nevrites  douloureuses  de  guerre  (Causalgie)  par  I'alcoohsa- 

tion  nerveuse  locale,  Presse  med.,  v.  24:  i.  No.  31,  1916,  p.  241. 
Veillet,  L.:  Traitement  de  la  maladie  de  raynaud  par  la  sympathectomie  periarterielle 
Bull,  et  mem.  Soc.  med.  d.  hop.  de  Par.,  Ser.  3,  v.  42:  May  31,  1918,  p.  571. 


CHAPTER  XXI 
AMPUTATION  NEUROMA 

Unfortunately  many  surgeons  have  considered  that  any  painful  ampu- 
tation stump  is  to  be  attributed  to  tender  severed  nerve  ends,  but  severed 
nerves  are  not  the  only  source  of  pain  in  amputation  stumps.  Thus  Hirsch 
and  Bunge  found  that  the  presence  of  periosteum  and  endosteum  over  the 
end  of  the  bone  tends  to  produce  a  tender  amputation  stump.  Generally, 
in  true  neuromas,  the  pain  is  localized  definitely  over  the  end  of  the  nerve  in 
one  or  more  nerves  of  the  region,  while  in  neuritis  of  the  ascending  type  the 
nerve  trunk  is  tender  to  pressure  even  some  little  distance  above  the  site  of 
injury  and  not  only  over  the  nerve  end.  When  the  nerve  trunk  is  implicated, 
pressure  over  it  causes  pain  similar  to  that  of  which  the  patient  complains. 
Of  course,  it  must  always  be  borne  in  mind  that  in  many  amputations,  pain 
and  dysesthesia  of  all  sensations  may  exist  on  a  purely  psychogenic  basis, 
that  is,  hysterical  or  neurotic.  These  must  be  carefully  differentiated  and 
the  surgeon  had  best  restrain  himself  in  the  diagnosis  of  amputation  neuroma, 
only  where  there  are  signs  of  definite  involvement  of  the  nerve  ends,  and 
recommend  for  nerve  operation  only  those  cases  in  which  such  signs  exist. 

Corner  (191 8)  has  tried  to  divide  painful  neuromas  into  several  forms, 
depending  on  the  nature  of  the  pain:  those  with  immediate  pain,  coming  on 
at  once  and  lasting  a  relatively  short  time;  and  those  with  pain  of  imtlamma- 
tion,  developing  later  and  due  to  an  ascending  neuritis.  This  form  is  generally 
superimposed  upon  the  immediate  pain  without  any  remission,  the  pain 
becoming  more  severe  and  more  persistent. 

He  believes  that  contraction  of  scar  tissues  about  newly  formed  neuraxes 
may  cause  pain  by  strangulation  which  persists  until  the  neuraxes  die  off  and 
then  gradually  diminishes.  Another  source  of  pain  may  be  from  nerve  ends 
which  have  become  fixed  on  the  bellies  of  the  adjacent  muscles,  and  are  drawn 
upon  with  each  contraction  of  the  muscle;  or  the  whole  nerve  trunk  may  be 
caught  in  the  amputation  flap  and  streched  over  the  end  of  the  stump.  This 
is  apt  to  occur  in  the  older  methods  of  amputation  where  flaps  are  transfixed. 
Unless  the  nerve  has  been  cut  very  high,  the  neuraxes  escape  from  the  nerve 
end  and  grow  into  the  scar  and  callus.     The  connective  tissue  may  serve  to 

456 


AMPUTATION    NEUROMA  457 

fix  the  nerve  trunk  in  the  wound  where  the  fibers  may  be  compressed  and  the 
trunk  subjected  to  tension  and  stretching  on  movement  of  the  limb. 

It  is  interesting  to  note  that  severed  nerves  without  amputation  of  the 
limb,  even  though  they  be  fLxed  in  scar  and  callus  and  with  the  outgrowing 
neuraxes  invading  all  the  contiguous  tissues,  seldom  give  rise  to  pain  similar 
to  that  found  in  painful  amputation  neuromas. 

Marinesco  (1918)  has  shown  in  his  study  of  painful  amputation  neuromas 
that  the  majority  of  them  show  evidences  of  a  generalized  infective  neuritis: 
endarteritis,  periarteritis,  perivascular  exudation,  and  infiltration  with  lym- 
phocytes and  leucocytes,  and  the  presence  of  giant  cells.  In  one  neuroma 
removed  three  years  after  amputation,  a  low-grade  infection  was  discovered 
with  bacteria  still  present.  In  a  number  of  neuromas  minute  foreign  bodies 
were  found. 

Histology. — A  neuroma  represents  an  attempt  at  regeneration  on  the  part 
i)f  a  severed  nerve  and  may  be  said  to  form  regularly  on  any  severed  nerve  unless 
prevented.  Neuromas  may  be  present  without  pain  and  even  without  undue 
sensitiveness  or  tenderness,  so  it  is  likely  that  painful  neuromas  present  addi- 
tional changes  within  the  nerve  of  an  irritative  character  not  found  when  simple 
enlargement  of  the  nerve  end  is  present.  No  clear  histological  characteristics 
have  been  determined  which  difi'erentiate  simple  non-painful  neuromas  from 
those  with  spontaneous  pain.  Infection  and  ascending  neuritis  may  play  a 
role;  yet  painful  neuromas  have  been  found  in  wounds  which  have  healed 
without  infection  and  in  which  there  was  little  or  no  scar  tissue.  That  the 
irritation  once  well  established  is  not  exerted  only  locally  may  be  assumed 
from  the  fact  that  in  secondary  operations  even  when  the  nerve  is  amputated 
\"ery  much  higher,  in  normal  muscle  planes  without  scar  or  infection  painful 
nerve  ends  frequently  reform. 

An  amputation  neuroma  consists  mainly  of  proliferated  endoneural  and 
perineural  connective  tissue,  neurolemma  cells  and  regenerating  neuraxes. 
The  neuraxes  may  follow  a  more  or  less  straight  course  as  they  enter  the  proxi- 
mal part  of  the  neuroma,  ])ut  soon  the  fibers  become  interlaced  and  many  of 
them  are  turned  back  on  themselves.  A  few  fibers  may  penetrate  the  connec- 
tive tissue  cap  which  forms  over  the  end  of  the  nerve  and  escape  into  the 
surrounding  tissues.  Numerous  end  discs  and  bulbs,  called  growth  cones,  are 
seen,  frequently  extremely  large,  and  many  branching  fibrils  are  met.  These 
en<l  discs  and  branching  fibrils  show  the  regenerative  power  of  the  neuraxes. 
When  certain  neuraxes  encounter  resistance,  the  fibrils  turnback  on  themselves 


4S8        SURGICAL   AND   MECHANICAL   TREATMENT    OF    PERIPHERAL   NERVES 


and  form  spirals  within  the  neurolemma  sheath,  curKng  around  the  neuraxes 
from  which  they  have  arisen.     These  are  termed  Perroncito  spirals,  and  in  a 

measure  indicate  the  degree  of  resistance  the  neuraxes 
have  encountered.  The  spirals  vary  in  size  and  shape, 
some  being  long  and  slender  and  others  short  and 
thick,  depending  somewhat  upon  the  direction  from 
which  they  meet  resistance.  They  may  be  found  in 
any  portion  of  the  neuroma  and  are  often  seen  in 
clusters.  The  spirals  give  off  numerous  small  branches 
with  end  discs. 

Marked  overgrowth  of  the  endoneural  and  perineu- 
ral connective  tissue  is  seen,  with  embryonal  charac- 
teristics retained  until  late.  In  older  neuromas  the 
tissue  contracts  and  sclerosis  takes  place.  Huber  and 
Lewis  (1920)  are  of  the  opinion  that  the  chief  factor 
in  amputation  neuromas  is  this  outgrowth  of  connec- 
tive tissue,  stimulated  to  increased  activity  by  the 
continuous  attempts  of  the  neuraxes  at  regeneration. 
"It  is  quite  probable  that  the  developing  neuraxes 
during  their  regenerative  activity  stimulate  this  connec- 
tive tissue  to  an  excessive  growth  which  continues  for 
some  time." 

Treatment. — Until  recently,  most  surgical  methods 
of  treating  amputation  neuroma  have  been  attempts 

to  prevent  the  escape  of  neuraxes  into  the  surround- 
FiG.  214. — Section  of  dis- 
tal end  of  pro.ximal  segment    ing  tissues.     Sicard   (1916),    Godelewski    (1916)   and 

of  a  rabbit's  sciatic  nerve,  90    others  have  tried  to  allay  the  pain  in  painful  amputa- 
days  after  injection  with  ab- 
solute alcohol.  Tapering  end    tio^"'  neuromas  by  injection  of  60%  alcohol  and  have 

of  nerve  wthout  any  evidence    reported  numerous  successes  with  this  method.     They 

of  neuroma  formation  may  be 

noted.    The  ends  of  nerves    claim  that  6o%  alcohol  causes  degeneration  of  only 

treated  in  this  way  often  pre-    t^g   sensory   neuraxes.     Huber   and  Lewis  were  the 

sent  in  the  earlier  stages  a 

peculiar  yellowish-white  ap-    ^rst    to   attempt   to  prevent    the   downgro-dth  of  all 

pearance  due  to  the  degener-    neuraxes.     These  investigators  used  absolute  alcohol 

ated    myelin.     (Huber     and 

Lewis,  Archives  of  Surgery,    which  causes  complete  degeneration  of  all  neuraxes  dis- 
'920)  tal  to  the  point  injected,  and  in  guinea  pigs,  rabbits  and 

dogs,  found  that  six  months  after  injection  such  amputated  nerves  presented  a 
apering,  finely  pointed  stump  with  little  or  no  tendency  to  bulb  formation. 


I 


AMPUTATION    NEUROMA 


459 


(See  Fig.  214.)  When  compared  with  controls,  the  difference  was  striking. 
In  the  early  stages  following  alcohol  injection,  in  place  of  the  neuraxes, 
myelin  and  neurolemma  cells,  granular  detritus  and  phagocj'tic  cells  were 
found.  (See  Fig.  215.)  In  later  stages,  downgrowing  young  nerve  fibers 
having  a  straight  course  with  little  or  no  criss-crossing  were  encountered, 
accompanied  by  bands  of  nucleated  protoplasm.  In  older  specimens,  the 
neuraxes  had  reached  the  distal  end  of  the  cut  nerve  in  parallel  bundles  without 


♦^s' •»■«»  J' 


,      .  JV 


Fig.  215. — EfiEects  of  absolute  alcohol  injection  on  neuraxes.  Finely  granular  remains  of 
degenerated  neuraxes.  Neurolemraal  sheaths,  many  of  which  remain,  are  filled  with  granular  masses 
and  globules  of  fat.     (Huber  and  Lewis,  Archives  of  Surgery,  1920.) 

interlacing  or  forming  Perroncito  spirals,  and  the  ends  of  all  nerve  trunks 
were  tapering  without  any  tendency  to  bulb  formation.  (See  Fig.  216.) 
Huber  and  Lewis  concluded  that  "  absolute  alcohol  injected  into  the  nerve  some 
distance  (from  three-quarters  to  an  inch  above  the  plane  of  section)  is  more 
successful  in  preventing  neuroma  formation  than  any  of  the  other  methods 
ordinarily  employed." 

Many  of  the  old  surgeries  show  ingenuous  figures  illustrating  attempts  to 
prevent  the  formation  of  neuromas.  In  them  wc  see  nerve  stumps  turned  upon 
themselves  and  sutured  to  the  parent  trunk,  nerves  split  and  sutured  again  to 


460        SURGICAL   AND   MECHANICAL   TREATMENT   OF   PERIPHERAL   NERVES 

each  other,  or  even  the  parent  trunk  slit  and  the  nerve  ends  passed  through  the 
opening,  and  then  sutured  to  the  trunk.  Any  method  which  inflicts  such 
additional  damage  to  the  parent  nerve  stem  is  apt  to  increase  the  neuraxis 
overgrowth  and  the  formation  of  scar,  thus  increasing  the  factors  for  neuroma 
building. 


Fig.  216. — Section  of  specimen,  go  days  after  injection.  Degenerated  neuraxes  and  myelin 
sheaths  are  seen  in  lower  part  of  the  field.  Straight  longitudinal  regenerating  neuraxes  are  seen  in 
upper  part.  No  evidences  of  spiral  formation  or  end  discs  in  this  section.  (Huber  and  Lewis, 
Archives  of  Surgery,  1920.) 

In  order  to  avoid  such  great  trauma  in  preventing  outgrowth  of  neuraxes ' 
Chappie  (1918)   attempted  to  turn  back  a  cuff  of  epineurium,  stripping  it  I 
upward  with  a  piece  of  gauze,  and  cutting  the  nerve  just  below  the  reflected 
cuff.     After  this  the  epineurium  was  brought  down  over  the  cut  surface  of  the . 
nerve.     This  method  being  based  on  an  erroneous  conception  of  the  factors 
which  bring  about  the  formation  of  a  neuroma  does  not  prevent  the  outgrowth 
of  neuraxes,  for  in  stripping  up  the  epineurium  multiple  minute  tears  occur 
through  which  not  only  the  neuraxes  may  escape  but  infection,  if  present,  may 
enter. 

By  making  a  wedge-shaped  or  inverted  V  incision  into  the  nerve   trunk 


I 


AMPUTATION   NEUROMA 


461 


Corner  (1918)  produces  a  "swinging-door  flap"  and  is  thus  able  to  close  off  the 
nerve  end  by  epineural  sutures.  This  method  is  comparatively  successful  in 
preventing  the  escape  of  neuraxes  providing  accurate  approximation  is  obtained, 
for  connective  tissue  union  takes  place  before  downgrowth  of  neuraxes  can  occur. 
The  great  and  only  value  of  this  method  is  that  it  permits  one  to  close  off  the 
nerve  stump  from  the  surrounding  field  and  possibly  prevent  an  ascending  neuritis 


^ 


Fig.  217. — Method  of  treating  nerve  ends  in  amputation  stumps.  The  nerve  ends  are  dosed 
by  Connor's  "swing-door"  method  to  ^prevent  an  ascending  infection  in  the  nerve — not  to  prevent 
I'utgrou'th  of  neuraxes.  Two  to  3  cm.  above  the  nerve  ends  absolute  alcohol  is  injected  so  as  to 
reach  all  parts  of  the  nerve  and  asecondseriesof  injections  is  carried  at  a  slightly  higher  level. 


in  those  cases  with  infection.     To  try  to  prevent  an  ascending  neuritis  is  the 
real  reason  for  closing  off  the  nerve  end  by  suture. 

Based  on  these  considerations  the  author  has  used  a  combination  of  Corner's 
closure  of  the  amputation  stump,  followed  by  alcohol  injection  2  or  3  cm. 
aboAe  the  point  of  section,  as  advised  by  Huber  and  Lewis.  The  alcohol 
should  be  injected  at  two  or  three  points  on  the  circumference  of  the  nerve  and 
repeated  again  at  a  slightly  higher  level  so  that  all  of  the  funiculi  may  be 
reached.     (See  Fig.  217.)     The  nerve  should  always  be  drawn  down  into  the 


462         SURGICAL   AND   MECHANICAL    TREATMENT    OF    PERIPHERAL    NERVES 

wound  and  cut  short  so  that  by  retraction  the  nerve  end  cannot  be  caught  and 
compressed  in  scar  and  callus. 

When  an  ascending  neuritis  involves  the  dorsal  ganglia  surgical  measures 
directed  toward  the  nerve  trunk  will  naturally  be  unsuccessful,  and  when 
more  than  one  nerve  is  involved  treatment  of  each  in  the  amputation  stump 
may  be  impracticable  due  to  difficulty  of  dissection  and  identification  in  scar 
tissue.  In  these  laminectomy  with  dorsal  root  section  may  be  tried,  although 
it  may  be  successful  in  only  a  small  percentage  of  the  patients. 

REFERENCES  I 

I 

Bardeistheuer:    Mitteilungen   aus   dem   Gebiete   der  Nervenchirurgie;  VI.     Behandlung   1 

der    Nerven    bei    Amputation    zur    \"erhutung    der    Amputationsneuromen,   Deutsch 

Ztschr.  f.  Chir.,  v.  96:  1908,  p.  128. 
Chapple,  W.  a.:  Reamputation,  Brit.  ^Med.  J.,  No.  2956,  v.  2:  1917  (Aug.  25),  p.  242. 

Prevention  of  nerve  bulbs  in  stumps,  Brit.  Med.  J.,  No.  2988,  v.  i:  191 8  (Apr.  6),  p.  399.  ; 
Corner,  E.  ^I.:  The  surgery  of  painful  amputation  stumps,  Proc.  of  the  Roy.  Soc.  of  Med., 

V.  2:  No.  7,  May,  1918,  p.  7. 
The  structure,  forms  and  conditions  of  the  ends  of  divided  nerves,  Brit.  J.  Surg.,  v.  6: 

1918-19,  p.  273.  I 

Nerves  in  amputation  stumps,  Brit.  Med.  J.,  No.  3047,  v.  i:  May  24,  1919,  p.  638. 
GoDELEWSKi:  See  Sicard,  J.:  Traitement  des  nevrites  douloureuses  de  guerre  (Causalgie)  , 

par  ralcoolisation  nerveuse  locale.  La  Presse  med.,  v.  24:  i.  No.  31,  1916,  p.  241.  I 

HuBER,  G.  C.  and  Dean  Lewis:  Amputation  neuromas:  their  development  and  prevention,  | 

.^rch.  Surg.,  v.  i:  No.  i,  July,  1920,  p.  85. 
Kruger:  Ueber  Nervenquetschung  zur  Verhiitung  schmerzhafter  Neurome  nach  Amputa- 

tionen,  Munchen.  med.  Wchnschr.,  v.  63:   1916,  p.  368.  I 

Maeinesco,  G.:  The  characteristics  of  amputation  neuromata,  Proc.  of  the  Roy.  Soc.  of 

Med.,  V.  2:  1917-18,  p.  5. 
Sicard,  J.  A.:  Traitement  des  nevrites  douloureuses  de  guerre  (Causalgie)  par  I'alcoolisa- 

tion  nerveuse  locale,  Presse  med.,  v.  24:  i,  No.  31,  1916,  p.  241. 


INDEX 


Note. — The  folios  in  ordinary  type  refer  to  text,  those  in  bold  face  to  pages  on  which  illus- 
trations occur. 


Abortive  autoregeneration,  51 

regeneration,  early,  52 
.\dductor  magnus  and   adductor  brevis,  nerve 
distribution  to,  383 
pollicis    muscle,    nerve    distribution    to,    351 
Adhesions,  mechanical  treatment  of,  189 
\dults,  injuries  of  brachial  plexus  in,  252,  253 
AlTcctive  sensations,  160 
Afferent  nerve,  17 
Agar  tubes,  125 

Airplane  splint  for  brachial  plexus  injury,  255 
Aknhol   injection,   effect   of,   on   neuraxes,  458, 
459.  460 
in  amputation  neuroma,  458,  461 
of  nerve  trunk  in  treatment  of  causalgia,  445 
Alcoholized    cargile    membrane,    Ruber's,    127 
Algesiometer,  159 

Amphioxus,  adult,  dorsal  root  and  ramus  ven- 
tralis  of,  transverse  section  through,  19 
spinal  nerves  from,  19 
motor  and  sensory  components  of  spinal  nerves 
in,  18,  18 
Amputation  neuroma,  456 

alcohol  injection  in,  458,  461 
histology,  457 
treatment,  458 
stumps,  method  of  treating  nerve  ends  in,  461 
Anastomosis,  nerve,  82 
Anesthetic  used  in  nerve  surgery,  138 
Apparatus,  ideal  for  correcting  deformities,  187 
.'\rterial  tubes,  123 

tubulization,  122,  123,  124 
technic,  123,  123 
Autogenous  grafts,  drawback  to  use  of,  loi 
Autoplastic  nerve  transplantation,  69.     See  also 

.\erve  transplanlalioii. 
Autoregeneration,  abortive,  51 
Axial  rotation,  minimal,  prevention  of,  difficult, 
38 
of    nerve    trunk,    avoiding,    in    nerve    su- 
ture, 142 
.\xolemma,  23 
Axone,  26,  23 


UxNDFASERN  of  Biinger,  42,  49 
Baths,  191 


Baths,  electrical,  192 

Bell's  palsy,  operative  indications  in,  208 

Bethe's  cell  chain  theory  of  origin  of  neuraxes, 

27,  44 
Bipolar     stimulation,     funicular     identification 

by,  34 
Birth   palsy,   rupture  of  seventh   cervical   root 

in,  239.     See  also  Brachial  plexus. 
Bone,  decalcified,  tubes,  122 
tubulization,  121 
resection  of,  for  diminishing  nerve  defect,  107 
Brachial  plexus,  220,  223,  224 
anatomical  considerations,  222 
cervical  ribs  complicating,  256 
anatomy,  256 
deformity  in,  258 
mechanical  treatment,  259 
sensory  changes  in,  258 
surgical  treatment,  259 
dorsal  cord  of,  exposure  and  suture  of,  280 
embryology  of,  220 

exposure  of,  above  clavicle  for  stab  wound 
of  fifth  and  sixth  cervical  roots,  253 
below  clavicle,  254 
of  secondary  cords  of,  311 
technic,  249 
gunshot  wounds  of,  255 
illustrating  mechanism  of  birth  injuries,  243 
injury  of,  airplane  splint  for,  255 
anatomical  types  of,  225 
in  adults,  252 

splint  for,  256,  233,  255,  276 
paralysis  of,  231 

lower  radicular  or  Duchenne-Aran  type, 

228,  234 
middle  radicular  type,  234 
obstetrical,  235 
deformity  in,  245 
duration  of  treatment  in,  245 
etiology,  238  ,  243,  244 
exercises  for,  246,  247 
historical,  236 

Horner's  syndrome  in,  237,  237 
late  mechanical  treatment,  246 
location  of  injury  to  nerve  roots  in,  240, 
239.  243-  244 


463 


464 


INDEX 


Brachial  plexus,  paralysis  of,  obstetrical,  me- 
chanical treatment,  245 

operation  in,  249 

pathology  of,  242,  239,  241,  242,  243, 
244 

secondary  injury  to  spinal  cord  in,  240 

splint  for,  233 

surgical  treatment  in  neglected  cases, 

251 
time  of  operation  in,  248 
operation  for,  253,  254 
types  of,  2 28 

upper  radicular  or  Duchenne-Erb  type, 
228,  232 
deformity  in,  232 
prefixed,  222,  223 
postfixed,  222,  224 

relation  of,  to  development  of  limb,  220 
right  and  left,   transverse  section   through 

cords  of,  241,  242 
ruptures  of,  235 
in  adults,  252 
secondary  cords  of,  exposure  of,  280,   298 

312,313 

seen  from  behind,  243,  244 

stab  wounds  of,  255,  253 

surgical  treatment  of,  in  presence  of  cervical 
rib,  256 
Bridging  nerve  defects,  68,  103.     See  also  Xerve 
^  Idcfecls. 

Bruns'  neuroplasty,  80 
Buerki's  splint  for  foot-drop,  410 
Biinger,  bandfasern  of,  49 

C.\BLE  autonerve  transplant,  72 
graft,  81 

transplant,  Si,  81 
in  place,  153 
in  sciatic  of  dog,  74 
26  days  after  suture,  73 
Caliper  for  paralysis  of  tibial  division  of  sciatic 
nerve,  411 
Thomas,     for    paralysis    of    anterior     crural 
nerve,  427 
Cargile  membrane,  in  nerve  surgery,  127 

Ruber's  alcohohzed,  1 2  7 
Causalgia,  445 

alcohol   injection    of   nerve    trunk    in    treat 

ment,  445 
of  median  nerve,  involvement  of  nerve  in  veil 

of  scar,  446,  448 
painful  phenomena  in,  449 
perivascular  sympathectomy  in,  449,  450,  451 
role  of  sympathetic  system  in,  447 
Cell  chain   theory  of  Bethe  of  origin  of   neu- 
raxes,  27,  44 


Cells,  motor,  nerve  stretching  causes  changes  in, 
103,  104 
sheath.  26 
origin  of,  26 

experimental  evidence  to  show,  27 
tj-pes  of,  26 
sympathetic,  migration  of,  29 
Central  flap  in  nerve  flap  repair,  87 
CerNncal  ribs  complicating  brachial  plexus,  256. 
See  also  Brachial  plexus. 
anatomy,  256 
deformity  in,  258 
mechanical  treatment,  259 
sensory  changes  in,  258 
surgical  treatment,  259 
surgery    of    brachial    plexus,    in    presence 
of,  256 
Chromatolysis,  central,  in  nerve  stretching,  103, 

104 
Circumflex  nerve,  297 
branches  of,  298,  298 
course.  297 

exposure  of.  298.  280,  299 
at  surgical  neck,  299 
in  axilla,  298 
injury  of,  deformity  from,  299 
mechanical  treatment,  300 
Collaterals  ending  in  facial  nucleus,  203 

in  hj'poglossal  nucleus.  202 
Compression,   nerve,  electrical  examination  in, 

164 
Conductivity,  nerve,  interrupted,  130 
Contractures,  mechanical  treatment  of,  189 
Crossing,  nerve,  82,  96 
complete,  82,  82 
downgrowth  of  neuraxes  in,  97 
hypoglossofacial,  197,  215 
incomplete,  82 
partial,  82,  83 

technic,  149,  149 
proper      coordination      of      proprioceptive 

stimuli  in,  96 
radial  and  median,  341 
spinofacial,  197,  2ii,  212,  214 
technic,  148 
Crural  nerve,  anterior,  420 
injury  of,  426 
deformity  in,  428 
mechanical  treatment,  428 
paralysis  of,  Thomas  caliper  for,  427 
surgical  treatment,  427 
Cutaneous  nerves  for  transplantation,  150,  314 
multiple  neurofibroma  from,  434,  435 

Decalcitied  bone  tubes,  122 
tubulization,  121 


i 


INDEX 


46; 


Defects,    nerve,    in    regeneration,    bridging,  68 

methods  for  diminishing,  103 
Deformity,  correction  of,  before  operation,  i8q 
from  anterior  crural  nerve  injury,  428 

mechanical  treatment,  428 
from  cervical  rib  complicating  brachial  plexus, 

258 
from  circumflex  nerve  injury,  2gg 
mechanical  treatment,  300 
from  complete  dorsal  cord  injuries,  275 

mechanical  treatment,  275 
from  Duchcnnc-Erb  paralysis,  232 

mechanical  treatment,  233 
from  long  thoracic  nerve  injury,  424 
mechanical  treatment,  425 
from  median  nerve  injury,  328 

mechanical  treatment,  330 
from  musculocutaneous  nerve  injury,  309 

mechanical  treatment,  310 
from  musculospiral  nerve  injury,  276 

mechanical  treatment,  277 
from  obturator  nerve  injury,  428 
from  peroneal  nerve  injury,  408 
mechanical  treatment,  408 
Robin-Chiray  device  in,  409,  409 
from  sciatic  nerve  injury,  406 

mechanical  treatment,  407,  427 
Thomas  caliper  in,  407,  427 
from  spinal  accessory  nerve  injury,  422 

mechanical  treatment,  423 
from  suprascapular  nerve  injury,  426 

mechanical  treatment,  426 
from  tibial  nerve  injury,  409 

mechanical  treatment,  410 
postural,  ideal  apparatus  for  correcting,  187 
Degenerating  nerve  fibers  of  peripheral  stump  of 

sciatic  of  rabbit,  48 
Degeneration  and  regeneration  of  nerve,  41 
of  medullated  nerve  fibers,  47 
of  nerve  endings,  50 
of  nerves,  complete,  reaction  of,  163 

secondary,  46 
of  nonmedullated  nerve  fibers,  50 
Wallerian,  41 
Deltoid  muscle,  right,  nerve  distribution  to,  297 
Denervatcd  muscle,  changes  in,  185 
physiological  changes  in,  185 
treatment  of,  during  stage  of  recovery,  193 
I  )oscendens  hypoglossi  and  hypoglossal  nerves, 

development  of,  206 
I  'irect  muscle  implantation,  117,  115 
nerve  implantation,  112,  113,   115,   116 
technic  of,  117,  116 
I  liscriminative  sensations,  160 
1  lissection  of  macerated  nerve  trunks,  33 
I  )issociation,  fibrillar,  53 

30 


Dorsal  cord  injuries,  complete,  275 
deformity  in,  275 
exposure  of,  280,  289,  298 
mechanical  treatment,  275 
splint  for,  276,  276 
dermatomes,  228 

primary  division  of  spinal  ner\c,  17 
root  and  ramus  ventralis  of  adult  amphioxus, 
transverse  section  through,  19 
of  spinal  nerve,  17 
Duchenne-Aran  paralysis,  228,  234 
Duchenne-Erb  paralysis,  228,  232 
deformity  in,  232 
mechanical  treatment,  233 

Efferent  nerve,  17 

Electrical  baths,  192 

examination  during  operation,  130 
in  nerve  compression,  164 
of  injured  nerves,  161 
of  nerves,  130 
response,  negative,  from  stimulation  of  nerve 

trunk  at  level  of  injury,  132 
treatment,  192 

Ellipsoids,  myelin,  47 

Elsberg's  method  of  nerve  graft,  153,  154 

End-to-end  suture,  83,  94 

inverted  V  method,  05.  95 

methods  which  should  not  be  used,  95 

nerves  prepared  for,  83 

oblique,  95,  95 

technic,  145,  146 

Endoneurium,  24.     Opposite  p.  34 

Entrance  and  exit  wounds,  possible  relation  of, 
to  course  of  missile,  158,  159 

Epineurium,  24,  145.     Opposite  p.  24 

Equality,  polar,  162 

Erb's  paradoxical  response  in  injured  nerves,  131 

Evulsion  of  funiculi  from  spinal  cord,  236 

Exploration,  nerve,  early,  175 

Extensor  digitorum   longus,   nerve   distribution 
to,  390 
group,  nerve  distribution  to,  389 

External  plantar  nerve,  exposure  of,  403 

Extremity,    lower,    development    of,    220,   372 
mechanical  treatment  of,  iSg 
rotation  of,  372 

variations  in  segmental  distribution  to,  374 
ventral    and    dorsal    musculature    of,    372 
position    of,    time    to    change,    after    opera- 
tion, 190 
upper,  220 

mechanical  treatment  of,  188 
muscles  of.  motor  root  supply  of,  226 
relation  of  brachial  plexus  to  development 
of,  220 


466  INDEX 


Extremity,  upper,  rotation  of,  221 

ventral    and    dorsal    musculature    of,    221 

Facial  muscles  in  facial  paralysis,  overstretch- 
ing, appliance  to  prevent,  216 
musculature,    proprioceptive    sense    of,    202 
nerve,  197 

congenital  maldevelopment  of,  2og 

cortical    connections,    200,    209,    199,    201 

crossing,  197 

choice  of  graft,  210 

choice  of  nerves,  204 

disassociation  of  associated  movements, 

198 
experimental  studies,  197 
with  hypoglossal  nerve,  197,  19S,  215 
with  spinal  accessory  nerve,  197,  198,  204 
with  spinofacial,  197,  ig8,  214 
exposure  of,  210,  211 
incision  for  operation  on,  210 
injury  at  birth,  209 
implantation  into  spinal  accessory,  197 
Hberation,  208 
operative  indications,  208 

technic,  210 
paralyses,  mechanical  treatment  in,  216 

operative  indications  in,  208,  209 
paralysis,  bilateral,  280 
transplantation,  autogenous,  210 
nucleus,  collaterals  ending  in,  200,  201,  203 
paralysis,  appliance  to  prevent  overstretching 
of  facial  muscles  in,  216 
from    otitis    media,    operative    indications 

in,  208 
operative  indications  in,  208,  209 
Failure  in  operations,  cause  of,  157 
Faradic   current   for   electrical   examination   of 

injured  nerves,  161 
Fascia  lata  in  tubulization,  126 
Fascial  tubulization,  126 
Fibers  of  Remak,  21, 
Fibrillar  dissociation,  53 
Fibroma  of  peripheral  nerves,  genesis,  4,39 
location,  433,  434 
malignant  degeneration  in,  438 
plexiform,  438 
treatment,  438 
Flap  method  of  nerve  repair,  86,  87 
central  flap  in,  87 
peripheral  flap  in,  88 
Flexor  carpi  ulnaris  muscle  showing  variation 
in  innervation,  350 
group  in  thigh,  nerve  distribution  to,  384 
muscles  in  arm,  nerve  distribution  to,  304 
Forearm,  distribution  of  musculospiral  nerve  to 
muscles  of,  269 


Foreign  body  in  partial  injury  of  nerve  trunk, 

279 
Foot-drop,  Robin-Chiray  device  for,  409,  409 

splint  for,  Buerki's,  410 
Frog  larva,  nerves  of  abdominal  wall  of,  27,  28 
Funicular     anatomy,     theoretical     importance 
of,  29 

identification  by  bipolar  stimulation,  34 
Funiculi,  24 

Galvanic  current  for  electrical  examination  of 

injured  nerves,  162 
Ganglionic  crest,  changes  in,  25 

formation  of,  24 
Gastrocnemius,  right,  nerve  distribution  to,  386 

400,  401,  402 
Gelatin  tubes,  125 

Gluteal  nerves,  superior  and  inferior,  429 
exposure,  430 
injury  of,  429 
surface  projection,  430 
Grafts,  autogenous,  drawback  to  use  of,   loi. 
See  Nerve  transplantaiion. 
cable,  81 
preserved,  loi 
Gray  rami  communicantes,  29 
Greffe  nerveuse,  80,  81 
Gunshot  wounds  of  brachial  plexus,  255 

Hamstring  muscles,  nerve  to,  377,  378 
Harrison's  experimental  work  to  show  origin  of 

neuraxes  and  sheath  cells,  28,  44 
Healing    of   nerves    by    primary   intention,    95 
Hemorrhage  between  nerve  ends  in  nerve  suture, 

147 
intraneural,   and  scar  formation  from  nerve  ' 

stretching,  105 
Hensen's  theory  of  origin  of  neuraxes,  27 
Hersage  in  nerve  liberation,  134 
Heteroplastic  nerve  transplantation,  69 
His',   outgrowth  theory  of  origin  of  neuraxes,  1 

27,  44 
Homoplastic  nerve  transplantation,  69 
Horner's  syndrome,  anatomical  basis  of,  237 

in  obstetrical  paralysis  of  brachial  plexus,  1 

237 
Ruber's    alcoholized    cargile     membrane,     127  ■ 
Hueter-Czerny    method    of    nerve    flap    opera- 
tion, 80 
Humerus  and  scapula,   tracings  showing  their 
relation   in   elevation   of   humerus,   230,   231 
Hypoglossal  and  descendens  hypoglossi  nerves, 
development  of,  205,  206 
nerve,  exposure  of,   213,  211,   212,   214,  215 

facial  nerve  crossing  with,  197 
nucleus,  collaterals  ending  in,  201,  202 


INDEX 


467 


Hyperneurotization,  115,  115 

nf  muscle  having  normal  nerve  supply,  115 
Ihpoglossofacial  nerve  crossing.  197,  215 
cortical  connections  in,  igp,  201 
suture,  213 

Identification   sutures   in    nerve   suture,    142 
Implantation,  muscle,  direct,  117,  115 

nerve,  81,  83,  92,  82.     See  also  Nerve  implanla- 
lioii. 
direct,  113,  116,  313 

muscle   curves   obtained   from   stimulation 
in,  114 
Incision,  skin,  in  nerve  suture,  141 
Incomplete  nerve  crossing,  82 
Indications  for  operation,  157.     See  also  Opera- 
lion,  indications  jar. 
Injections,  alcohol,  effect  of,   on  neuraxes,  458, 
459,  460 
in  amputation  neuroma,  45S 
of  nerve  trunk  in  treatment  of  causalgia,  445 
Instruments,  138 
Intermediate  regions,  35 
Internal  nerve  plexuses,  35 
plantar  nerve,  exposure  of,  403 
topography,  StotTel's  views  on,  evidence  not 
in  support  of,  30 
Interosseous  nerve,  posterior,  exposure  of,  2S7, 

287,  288 
Interrupted  nerve  conductivity,  130 
regeneration  and  reoperation,  171 
intraneural  dissection  in  nerve  liberation,   133 
hemorrhage  and  scar  formation  from   nerve 

stretching,  105 
injection    of    salt    solution    in    nerve    libera- 
'         tion,  133 

'     scar,  density  of,  estimating  in  nerve  injury,  132 
Ischemia  of  extremities  interfering  with  regenera- 
tion, 177 

Lapicque's    method   of   electrical    stimulation, 
,     192,  193 
jLaryngeal   muscles,   neurotization  of,  Hoessly's 

technic,  421 
nerve,  recurrent,  419 
I  direct  implantation  of,  420,  420 

i  suture  of,  419 

[Leprosy,  peripheral  nerves  in,  442 
li.e  signe  du  fourmillement  as  contraindication  to 

operation,  i66 
(Level  of  suture,  144 

jLiberation    of    nerves,     130.     See    also    Nerve 
I  liberation. 

I        electrical  examination  of  nerve  in,  130 

excision  of  scar  in,  134 

nerve  section  in,  133 


Liberation  of  nerves,  results  of,  134 

Limb  buds,  development  of,  220 

Longitudinal  reaction,  162 

Lower  extremity,  mechanical  rreatment  of,  198. 

See  also  Extremity  lower. 
radicular  or  Duchenne-Aran  type  of  brachial 

plexus  paralysis,  232 
Lumbosacral  plexus,  372,  373 

embryological  development,  372 

injury  to,  375 

prefixed,  374 

primitive  distribution  of,  373 

postfixed,  374 

variations  in  segmental  contributions  to,  374 

Macerated  dissection  of  left  ulnar  and  median 
nerves,  31 
of  median  and  musculocutaneous  nerves,  32 
nerve  trunks,  dissection  of,  a 
Magnesium  tubes,  125 
Massage,  191 

Mechanical  treatment,  183,  186 
apparatus  for,  187 
associated  treatment,  191 
baths  in,  191 
early,  188 
late,  189 
massage  in,  191 
of  lower  extremity,  189 
of  upper  extremity,  188 
purpose  of,  184 
Median  and  musculocutaneous  nerves,   macre- 
ated  dissection  of,  32,  322 
and  ulnar  nerves,  association  in  distribution 
of,  329 
communications  between,  325,  326 

in  hand,  326 
e.xposure  of,  below  pectoralis  major,  333, 

334.  335,  336 
left,  macerated  dissection  of,  31 
macerated  dissection  showing  communica- 
tion between,  352 
nerve,  316 

abnormalities  in  distribution,  306,  307 
anatomy,  316 
anomalies,  325 
branches,  319,  320 
at  wrist,  325 
in  arm,  319,  280,  298,  313,  333,  334,  335, 

336,  446,  448 
in  forearm,  319,  321,  340 
motor,  in  lower  part  of  arm,  310 
causalgia,  involvement  of  nerve  in    veil  of 

scar,  446,  448 
complete    interruption  of,  with  connective 
tissue  continuity  of  ulnar  nerve,  338 


468 


INDEX 


Median    nerve,    complete    severance    of,  below 
pronator  teres,  340 
course,  316 

crossing  with  radial,  341 
exposure  of,  332 

at  elbow,  as,  337.  338,  339 
at  wrist,  364 

human,   cross   section,   32,    33,    322,   323 
injury  of,  deformity  in,  328 
mechanical  treatment,  330 
splint  for.  330 
transplantation  in,  100 
left,  macerated  dissection,  323 
macerated  dissection   showing  communica- 
tion with  musculocutaneous  nerve,  320 
neurofibroma   of,  327,  435,  436,   437,     See 

Tumors. 
paralysis  of,  splints  for,  331,  332 
regeneration  in,  341 
relation  of,  to  axillary  and  brachial  artery, 

318 
showing     communication     with      musculo- 

spiral  nerve,  308 
surface  projection,  316 

variations    in    formation    and    course,    317, 
317,318 
ileduUa  of  rabbit  five  days  after  evulsion  of  left 

hypoglossal  nerve,  104 
Medullary  sheath,  23 
MeduUated  fibers  of  spinal  nerve,  23 

nerve  fibers,  degeneration  of,  47 
Membrane,  cargile,  Ruber's  alcoholized,  127 

in  nerve  surgery,  127 
ilctabolic  changes  in  muscle,  165 
Middle  radicular  type  of  brachial  plexus  paraly- 
sis, 234 
Migration  of  sympathetic  cells,  29 
Minimal  axial  rotation,  prevention  of,  difficult, 

38 
Mixed  nerves,  1 7 

ilobilization  of  nerve,  for  defect,  103 
Motor  and  sensory  components  of  spinal  nerves 
in  Amphioxus,  iS 
endings  in  regeneration,  overproduction  of,  65 
nerve,  17 

neurone,  peripheral,  22 

root  supply  of  muscles  of  upper  extremity,  226 
Movements,  shoulder  girdle,  mechanism  of,  229, 

230 
Muscle,  catabolic  changes  in,  165 
composite,  222 
denervated,  changes  in,  185 
physiological  changes  in,  1S5 
treatment  of,  during  stage  of  recovery,  193 
implantation  direct,  117,  115 
paralyzed,    muscular    neurotization    of,    115 


Muscle,  striated,  motor  terminations  in.  during, 

degeneration  of  peripheral  nerve,  50 
Muscles,  deep,  of  calf,  nerve  distribution  to,  388 
laryngeal,  neurotization  of,  Hoessly's  technic, 

42r 
of  forearm,  distribution  of  musculospiral  nerve 

to,  269 
of  upper  extremity,  motor  root  supply  of,  226 
re-education  of,  193 
Muscular    neurotization,  methods  of  obtaining, 
118 
of  paralyzed  muscle,  115 
Musculocutaneous  nerve,  302 

abnormalities  in  distribution,  306,  307 

anatomy,  302 

and   median   nerve,    macerated   dissection, 

32,  322 
anomalies  of,  303 
branches,  302,  304 
course,  302 

exposure  of,  at  origin  with  direct  implanta- 
tion of  nerve  into  biceps  muscle,  313 
in  axilla,  310,  298,  312 
of  cutaneous  branch,  314 
of  middle  third  of,  314 
injury  of,  deformity  in,  309 
macerated  dissection  showing    communica- 
tion with  median  nerve,  320 
mechanical  treatment,  310 
paralysis  of,  wrist  strap  for,  310,  310 
surface  projection,  303 
Musculospiral  nerve,  265 
anatomy,  265 

anomalies  of  distribution,  274 
branches,  266,  267 

terminal,  272 
course,  265,  266 
cross  section  of,  273 
crossing  with  median,  341 
dissection  of  macerated  specimen,  270,  271 
dissociated  paralysis  of,  279 

foreign  body  in,  279 
distribution  to  muscles  of  forearm.  269 
exposure  of.  280,  283,  298 

behind  humerus  and  immediately  below  ^ 

teres  major  tendon,  279,  298 
of  lower  third,  286 
of  lower  two-thirds,  284,  285 
of  upper  third,  line  of  incision  for,  282 
injury  of,  276 
deformity  in,  276 
dissociated  paralyses,  279.  279 
exposure  of,  280 
in  arm,  281 
incision  for,  282 
mechanical  treatment,  277 


INDEX 


469 


Musculospiral    nerve,    injury    of.    regeneration 
following  suture  of,  igi 
splint  for,  277,  278 
transposition  of,  289,  289,  290 
macerated  dissection  of  median  nerve  show- 
ing communication  with,  308 
nerve  plexuses  in,  374 
right  and  left  of  same    individual,    level  of 

nerve  plexuses  in,  273 
surface  projection,  266 
terminal  branches,  272 
transposition  of,  289,  290 
variations  in,  265 
Myelin,  23 
and   neuraxes   removal   of,    in     degenerating 

peripheral  fiber,  49 
ellipsoids,  47 
sheath,  23 
Myelinated  nerve  fiber,  23 
Myotomes,  26,  220 

Neokixetic  system  in  peripheral   nerves,   165 
Nerve  anastomosis,  82 

circumflex,   297.     See  also    Circiinijiex  nerve. 

compression,  electrical  examination  in.  164 

conductivity,  interrupted.  130 

cross  section  of,   24,   32,   33,   273,   322,  323, 

394 

crossing,  82,  96 
complete,  82,  82 
downgrowth  of  neuraxes  in,  97 
hypoglossofacial,  197,  215 
incomplete,  82 
partial,  82,  82 

technic,  149,  149 
proper  coordination  of  proprioceptive  stim- 
uli in,  96 
spinofacial,  197,  211,  212,  214 
technic,  148 
crural,  anterior,  426.     .See  also  Crural    nerve 

anterior. 
defects  in  regeneration,  bridging,  68 

methods  for  diminishing.  103 
degeneration  and  regeneration,  41.     See  also 

Degeneration. 
distribution  to  adductor  magnus  and  adductor 
brevis,  383 
to  adductor  poUicis  muscle,  351 
to  deep  muscles  of  calf,  388 
to  extensor  group  and  peroneus  brevis,  389 
to  flexor  carpi  ulnaris,  350 

and   flexor   digitorum    profundus, 
and   flexor  pollicis  longus,    329 
digitorum  sublimis,  321 
group  in  thigh.  384 
muscles  in  arm,  304 


Nerve    distribution    to    inferior    gluteal,    popli- 
teal, posterior  tibial  and  peroneal  arteries, 
453 
to  medial  and  lateral  plantar  arteries    and 

branches,  453 
to    peroneus    longus,    extensor      digitorum 

longus  and  peroneus  tertius,  390 
to  right  deltoid  muscle.  297 

gastrocnemius,  386 
to  soleus  muscle,  387 
to  thenar  muscles,  deep  surface,  326 
to  triceps  muscle,  267 
electrical  examination  of,  during  operation,  130 
ends,  degeneration  of,  5c 

hemorrhage  between,  in  nerve  suture,   147 
in  amputation  stumps,  method  of  treating, 

461 
prepared  for  end-to-end  suture,  83 
exploration,  early,  175 
facial,  197.     See  also  Facial  nerve. 
fibers,  degenerating,  of  peripheral    stump  of 
sciatic  of  rabbit,  48 
from  peripheral  stump  of  sciatic  of  rabbit.  47 
mcdullated,  degeneration  of,  47 
m\-elinated,  23 

nonmedullatcd,  degeneration  of.  50 
flap  method,  86,  87 
central  flap  in,  87 
experimental  evidence,  90 
peripheral  flap  in,  88 
technical  considerations  of,  87 
operations  to  1914,  summary  of,  84,  85 
gluteal,  inferior,  429.     See  also   Gluteal  nerves. 

superior,  429.     See  also  Gluteal  nerves. 
graft.     See  Nerve  Transplantation. 
hypoglossal.     See  Hypoglossal  Nerve. 
implantation,  81,  83,  92,  82 
direct,  112,  113,  116 
muscle  curves  obtained   from    stimulation 

in,  114 
technic,  117 
injuries,  groups  of,  175 

of  head  and  upper   extremity  relative   fre- 
quency of,  table  showing,  221 
of    lower    extremity,    relative     frequency, 

table  showing,  375 
relative  frequency  of,  table  showing,  173 
laryngeal,  419.     See  also  Laryngeal  nerve. 
liberation.  130 

and   nerve   suture   relative   frequency   of, 

table  showing,  134 
density  of  intraneural  scar  in,  132 
hersage  in,  134 
intraneural  dissection  in,  133 

injection  of  salt  solution  in,  r33 
results  in,  r34 


47° 


INDEX 


Nerve  liberation,  technic,  134 
vs.  nerve  suture,  133 
long  thoracic,  424.      See  also  Tlwrjcic  nerve, 

long. 
median,  316.     See  also  Med  hi  it  nerve. 
mobilization  of,  for  defect,  103 
musculocutaneous,   302.     See   also   Miiscido- 

culaneous  nerve. 
musculospiral,    265.     See  also   Musculospiral 

nerve. 
obturator,  428.     See  also  Ohluraior  nerve. 
operations  on,  157.     See  also  Operation. 
peroneal,  404.     See  also  Peroneal  nerve. 
plexuses,  internal,  35 
regeneration  of,  34 
repair,  methods  of.  So 
to  be  discarded,  86 
to  be  used,  94 
specific  terms,  80 
standardization  of  terms,  80 
retraction,  139 
roots,   location   of   injury   to,   in   obstetrical 

paralysis  of  brachial  plexus,  240,  239 
sciatic,  377.     See  also  Sciatic  nerve. 
spinal  accessory,  421.     See  also  Spinal  acces- 
sory nerve. 
stretching,  central  chromatolysis  in,  ro3,  104 
for  defect,  103 
in  suture  of  nerves,  142 
supply  to  radial  and  ulnar  arteries  and  super- 
ficial volar  arch,  452 
suprascapular,  425.     See  also    Suprascapular 

nerve. 
surgery,  cargile  membrane  in,  127 
suture  and  nerve  liberation,  relative  frequency 
of,  table  showing,  134 
end-to-end,  83 

inverted  V  method,  95 
methods  which  should  not  be  used,  95 
nerves  prepared  for,  83 
oblique  method,  95 
primary,  86 
secondary,  86 
technic,  146 
technic,  136 

anesthetic  in,  138 

arrangement  of  operative  field,  r36 

end-to-end,  r45 

general  operative  technic,  138 

hemorrhage  between  nerve  ends  in,  147 

instruments  for,  138 

level  of  suture  in,  143 

materials  used,  136,  137 

nerve  stretching  in,  142 

rotation  of  nerve  trunk  in,  avoiding,  142 

skin  incision,  141 


Nerve    suture,    technic,    special    incisions,    141, 
281,  395 
use  of  tourniquet,  I4r 
vs.  nerve  liberation,  133 
sutured,     longitudinal     section     through,     at 

point  of  suture,  137 
tibial,  403.     See  also  Tibial  nerve. 
to  hamstrings,  377,  378,  397 
transplantation,  67,  80,  98,  72,  73,  74,  81 
autogenous  grafts,  drawbacks  to  use  of,  loi 
autoplastic,  69 

cable  autonerve  transplant,  72 
graft  in,  81,  81 
transplant  in,  81,  81 
in  place,  153 
in  sciatic  of  dog,  74 
26  days  after  suture,  73 
heteroplastic,  69 
homoplastic,  69 
preserved  grafts,  loi 
re-exploration  in,  lor 

technic,  149,  15°)  i53.  151.  152,  I53>  336,  ' 
362,  363 
cable  transplant  in  place,  153 
Elsberg's  method,  153,  154 
Stookey's  method,  150 
value  of,  99 

why  downgrowth  may  not  take  place  in,  150 
transposition  of  for  defect,  106,  35S,  289,  339, 

356,  359 
trunk,  alcohol  injection  of,  in  treatment  of 
causalgia,  445 
macerated,  dissection  of,  ;}3 
rotation  of,  avoiding,  in  suture  of  nerves,  142 
ulnar,  347.     See  also  Ulnar  nerve. 
with  scar  to  be  excised,  144 
Nervenpfropfung,  8r 
Nerves  infrequently  injured,  419 

injured,   Erb's  paradoxical  response   in,   131 
of  abdominal  wall  of  frog  larva,  27,  28 
origin  of,  from  sciatic  plexuses  in  man,  36 
spinal,  18.     See  also  Spinal  nerre. 
Neuraxes  and  myelin,  removal  of,  in  degenerat- 
ing peripheral  fiber,  49 
effect  of  alcohol  injection  on,  458,  459,  460 
origin  of,  cell  chain  theory  of  Bethe,  27,  44 
experimental  evidence  to  show,  27 
Harrison's  experimental  work,  28,  44 
Hansen's  theory,  27 
outgrowth  theory  of  His,  27,  44 
silver    method    for    differential    staining    of, 
especially  young  and  growing  neuraxes,  44, 

45,  46 
Neuraxis  of  spinal  nerve,  22 
Neuroblastoma  of  peripheral  nerves,  440,  44l>lj 

442, 443.     See  Tumors. 


INDEX 


471 


Neuroblasts,  26 

Xcurotibroraa,  multiple,  from  cutaneous  nerves, 
434.  435-     See  Tumors. 
plexiform,  of  peripheral  nerves,  438 
of  median  nerve,  327,  43s,  436,  437 
of  sciatic  nerve,  secondary  malignant  degen- 
eration of,  438 
of  ulnar  nerve,  433,  441,  442,  443, 
Neurokeratin,  i;:,,  140 
Neurolemma,  23 
sheaths,     behavior    and     ultimate     fate     of, 
during  degeneration  of  peripheral  nerve,  53 
Neuroma,  amputation,  456 
alcohol  injection  in,  458 
histology,  457 
treatment,  458 
of  peripheral  nerves,  433 
Neurone,  motor,  peripheral,  22 
Neuroplasty,  So 
Neurorrhaphy,  80 
Neurosarcoma,   primary,   of  peripheral   nerves, 

440.     See  Tumors. 
Neurotization,    muscular,    methods    of    obtain- 
ing, irS 
of  paralyzed  muscle.  115 
of  laryngeal  muscles,  Hoessly's  technic,  421 
Vodale,  zone,  35  • 
Nodes  of  Ranvier,  23 

Nonmedullated  nerve  fibers,  degeneration  of,  50 
of  spinal  nerve,  23 
sheath  of,  23 
Nonmyelinated  fibers  of  spinal  nerve,  23.     See 
also  Nonmedullated  nerve  fibers. 

Obstetrical  palsy,  236 

paralysis  of  brachial  plexus,   235.     See  also 
Brachial  plexus. 
•Jbturator  nerve,  428 
exposure,  429 
injury  of,  428 
deformity  in,  42S 
Operation,  causes  of  failure,  157 
indications  for,  157 

criteria  for  estimating  results  in,  171 
electrical  examinations  in,  161 

results  of,  163 
interrupted  regeneration  in,  171 
le  signe  du  fourmillement,  166 
local  examination  in,  157,  158 
motor  examination  in,  161 
sensory  examination  in,  158 
signs  of  regeneration  in,  164 
time  of  regeneration  following  suture,  16S 
Tinel's  sign  in,  166 
value  of  complete  history  in,  157 
time  for,  172 


Operation,  time  for,  absence  of  progressive  re- 
generation in,  173,  174 
early  nerve  exploration  in,  175 
sterile  field  in,  173 
Operations  on  various  nerves,  relative  frequency 

of,  table  showing,  172 
Otitis   media,   facial   paralysis   from,   operative 

indications  in,  208 
Outgrowth  theory  of  His  of  origin  of  neuraxes, 
27,  44 

Paleokinetic  system  in  peripheral  nerves,  165 
Palsy,  obstetrical,  236.  See  also  Brachial  plexus. 
Paradoxical  response,  Erb's,  in  injured  nerves, 

131 
Paralysis,  Bell's,  operative  indications  in,  208 
Duchenne-Aran,  228,  234 
Duchenne-Erb,  228,  232 
deformity  in,  232 
mechanical  treatment,  233 
facial,  from  otitis  media,  operative  indications 
in,  208 
mechanical  treatment  in,  216 
operative  indications  in,  208,  209 
obstetrical,    235.     See   also   Brachial   plexus. 
etiology,  238 
historical,  236 

location  of  injury  to  nerve  roots  in,  240,  239 
mechanical  treatment  in,  245 
operation  for,  249 
pathology,  242 

secondary  injury  to  spinal  cord  in,  240 
surgical  treatment  in  neglected  cases,  251 
time  of  operation,  248 
of   brachial   plexus,    231.     See   also   Brachial 
plexus. 
Duchenne-Aran,  228,  234 
Duchenne-Erb,  228,  232 
obstetric,  235.     See  also  Brachial  plexus. 
types  of,  228 
resulting  from  section  of  substituted  nerve,  204 
Paralyzed  muscle,  muscular  neurotization  of,  115 
Partial  nerve  crossing,  82,  83 
technic,  149 
suture  of  sciatic  nerve  in  injury  of  peroneal 
division,  144,  397 
Pectoralis  major  muscle,  insertion  of,  exposure 

of,  298 
Perforation  of  sciatic  nerve,  partial  suture  of, 

after  excision  of  scar  tissue,  145 
Perineurium,  24 

Peripheral  flap  in  nerve  flap  repair,  88 
motor  neurone,  22 

nerves,  degeneration  of,  behavior  and  ulti- 
mate fate  of  neurolemma  sheaths 
during,  53 


472 


INDEX 


Peripheral    nerves    deReneration    of,    behavior 
of  motor  terminations  in  striated  muscle 
during,  50 
development  of,  24 
fibroma  of,  433 
genesis,  439 
location,  434 

malignant  degeneration  in,  438 
treatment,  438 
funicular  anatomy  of,  29 

theoretical  importance  of,  29 
in  leprosy,  442 

injuries,  relative  frequency  of,  table  show- 
ing, 174 
neuroblastoma  of,  440,  441,  442,  443.     See 

Tumors. 
neuroma  of,  433 
neurosarcoma  of,  primary,  440 
plexiform  neurofibroma  of,  438 
proximal  end,  of  cat  72  days  after  section,  66 
regeneration  of,  54 
tumors  of,  433 
stump  of  nerve  of  rabbit  27  days  after  section, 
newly  formed  neuraxes  in,  63 
of    sciatic    of    rabbit,    degenerating    nerve 
fibers  from,  48 
nerve  fibers  from,  47 
Perivascular  sympathectomy  in  causalgia,  449, 

4  SO,  451 
in  synesthesialgia  and  ulnar  nerve  injury,  450 
Peroneal  nerve,  exposure  of.  404,  404 
injury,  deformity  in,  408 
mechanical  treatment,  408 
Robin-Chiray  device  in,  409 
left,   extensive  injury  of,   with   callus  and 

scar  formation,  406 
paralysis   of,   appliances   for   correction  of 

deformities  in,  409,  410,  411 
surface  projection,  381 
suture  of,  results,  412 
Peroneus  brevis,  nerve  distribution  to,  389 
longus,  nerve  distribution  to,  390 
tertius,  nerve  distribution  to,  390 
Petromyzon,  motor  and  sensory  components  of 

spinal  nerves  in,  18 
Plantar  nerves,  internal  and  external,  exposure 

of,  403 
Plexiform  neurofibroma  of  peripheral  nerves,  438 
Plexus,  prefixed  type,  223 

postfixed  type,  224 
Plexuses,  nerve,  internal,  33,  35 
Polar  equality,  162 
Polarity,  reversal  of,  162 

Polistotrema,    adult,    spinal    nerve    and    vagus 
trunk  from.  28 
embryological  development  of,  21 


Popliteal  nerves,  exposure  of,  399,  400,  401 
Position   of   extremity,    time   to   change,   after 

operation,  iqo 
Possible  relation  of  entrance  and  exit  wounds  to 

course  of  missile,  158 
Postaxial  border,  221,  372 
Posterior  interosseous  nerve,  exposure  of,  287, 

287,  288 
Postfixed  type  of  plexus,  222,  224 
Preaxial  border,  221,372 
Prefixed  type  of  plexus,  222,  223 
Premuscle  mass,  221 

Preserved  grafts,  loi.     See  Xervelraiisplantalion. 
Pressure    on    nerve,    interrupted     conductivity 

from,  130 
Primary  neurosarcoma  of  peripheral  nerves,  440 

sutures,  86 

union  of  nerves,  95 
Proprioceptive  impulses,  confusion  of,  178 
Purposive  movements,  loss  of,  178 

Rami  collateralis  nervi  mediani,  319 

Ramus  ventralis  and  dorsal  root  of  adult  Am- 
phioxus,  transverse  section  through,  19 

Ranvier,  nodes  of,  23 

Reaction,  longitudinal.  162 
of  complete  degeneration,  163 
zone  of,  53 

Recurrent  laryngeal  nerve,  419 

direct  implantation  of,  420,  420 
suture  of.  41Q 

Re-education,  193 

Reflex  mechanism,  disturbed,  178 

Regeneration,  41 
abortive,  early,  52 

following  suture  of  musculospiral  nerve,  291 
table  showing.  170 
time  of,  168 
interrupted,  and  reoperation,  171 
of  a  peripheral  nerve.  54 
signs  of,  as  indications  for  operation,  164 
successful,  factors  interfering  with,  176 

Regions,  intermediate,  35 

Remak,  fibers  of,  23 

Reoperation,  interrupted  regeneration  and,  171 

Resection  of  bone,   for  diminishing   nerve  de- 
fect, 107 

Response,  negative,  in  nerve  trunk  from  stimula- 
tion at  level  of  injury,  132 

Retraction,  nerve,  139 

Reversal  of  polarity,  162 

Ribs,  cervical,  anatomy,  256 

surgery    of    brachial    plexus,    in    presence 
of,  255 

Robin-Chiray  device  for  deformity  of   peronea 
nerve  injury,  409 


INDEX 


473 


Robin-Chiray  device  for  foot-drop,  409 
Rotation,  axial,  minimal,  prevention  of, difficult, 38 

of  nerve  trunk,  avoiding,  in  nerve  suture,  142 
Rubber  tubing  in  tubulization,   125.     See  also 

Tubulhation. 
Ruptures  of  brachial  plexus,  235 
in  adults,  252 

Sarcoplasm,  165 

Sarcostyles,  165 

>capula    and   humerus,   tracings   showing   their 

relation  in  elevation  of  humerus,  230,  231 
Schwann,  sheath  of,  23,  26 
Sciatic  nerve,  377,  377  392,  397 
anatomy,  377 

arteries  and  veins  of,  injected  in  infant,  380 
branches  in  leg,  3S2 
in  popliteal  space,  382 

and  leg,  385,  387,  388,  389,  390 
in  thigh,  382,  383,  384 
course  in  leg,  379 

in  thigh,  378 
exposure  of,  395,  397 

in  popliteal  space,  jqg,  399,  400,  401,  402 
in  thigh,  398,  399 
of  upper  third,  395,  397 
skin  incision  for,  396 
injury  of,  deformity  in,  406 

mechanical  treatment,  407,  408,  409,  410, 

427 
Thomas  caliper  in,  407,  427 
transplantation  in,  100 
neurofibroma  of,  secondary  malignant  de- 
generation   of,    438.     See    also    Tumors. 
of  cat,  end  of  central  stump  of,  2]-^  days 
after  section.  56 
3   days  after  section,  57 
of  dog,  distal  portion  of  central  stump,  32 

days  after  section,  58 
paralysis  of,  splint  for,  408 

tibial  division  of,  caliper  for,  411 
partial    suture    of,    in    injury    of    peroneal 

division,  144 
perforation  of,  partial  suture  after  excision 

of  scar  tissue,  145 
peroneal  divison  of,  unicular  antomy,    391, 

392,  394 

surface  projection,  377,  378 

tibial     division     of,     funicular     anatomy, 

393,  392,  394 

plexuses  in  man,  origin  of  nerves  from,  36,  392 
Secondary  degeneration  of  nerves,  46 

sutures,  86 
Sensory  and  motor  components  of  spinal  nerves 
in  Amphioxus,  18 

nerve,  17 


Seventh    cervical    root,    rupture    of,    in    birth 

palsy,  240 
Sever  and  Thomas'  operation  in  neglected  cases 

of  obstetrical  brachial  plexus  paralysis,  251 
Shark,  spinal  nerves  in,  21 
Sheath  cells,  26 
origin  of,  26 

experimental  evidence  to  show,  27 
types  of,  26 
medullary,  23 
myelin,  23 
neurolemma,  behavior  and  ultimate  fate  of, 
during  degeneration  of  peripheral  nerve,  53 
of  nonmedullated  fiber,  23 
of  Schwann,  23,  26 
Shoulder     girdle     movements,     mechanism     of, 

229,  230,  231 
Sign,    Tinel's    as    contraindication    to    opera- 
tion, 166 
Silver    methods     for    differential     staining    of 
neuraxes,     especially     young     and     growing 
neuraxes,  44,  45,  46 
Skin  incision  in  nerve  suture,  141 
Soleus  muscle,  nerve  distribution  to,  387 
Somatopleure,  220 

Spinal  accessory  nerve,  exposure  of,  212,  212,  423 
anatomy  in,  422 
course,  422 
deformity  in,  422 

facial  nerve  implantation  into.  197 
injury  of,  421 
mechanical  treatment,  423 
variations  in,  422 
cord,     secondary    injury     to,    in    obstetrical 

paralysis  of  brachial  plexus,  240,  239 
nerve,  typical  18 
anatomy  of,  17 

and  vagus  trunk  from  adult  Polistotrema,  20 
comparative  anatomy,  18 
dorsal  primary  division  of,  17 

root  of,  17 
formation  of,  from  12  mm.  pig  embryo,  24 
from  adult  Amphioxus,  19 
gross  anatomy,  17 
histology,  22 
in  shark,  21 
meduUated  fibers,  23 
neuraxis  of,  22 
nonmedullated  fibers,  23 
ventral  primary  division  of,  1 7 
root  of,  1 7 
Spinofacial  nerve  crossing,   197,  211,   212,   214 

cortical  connections  in,  199,  201 
Splint,  airplane,  for  brachial  plexus  injury,  255 
for  deformity  in  dorsal  cord  injury,  276 
for  foot-drop,  Buerki's,  410 


474 


INDEX 


Splint  for  paralysis  of  brachial  plexus,  233 
of  median  nerve,  331,  332 
of  sciatic  nerve,  408 
of  ulnar  nerve,  353,  .^-^4,  354,  355 
for  wrist-drop,  277,  278 
Spongioblasts,  26 

Spring  device  for  correction  of  deformities    in 
peroneal  nerve  paralysis,  40S,  408,  409,  410, 
411 
Stab  wounds  of  brachial  plexus,  25s 

exposure  for,  253 
Standardization  of  terms,  80 
Stimulation,    bipolar,    funicular    indentification 

by,  34 
Stoffel's  views  on  internal  topography,  evidence 

not  in  support  of,  30 
Stookey's    method    of    nerve    graft,    150.     See 

Xervc  Iransplanlalion. 
Stretching,  nerve,  central  chromatolysis  in,  103, 
104 
for  defect,  103 
in  suture  of  nerves,  142 
Striated  muscle,  motor  terminations  in,  during 

degeneration  of  peripheral  nerve,  50 
Stumps,  amputation,  method  of  treating  nerve 

ends  in,  461 
Suprascapular  nerve,  anatomy,  426 
exposure,  426 
injury  of,  425 
deformity  in,  426 
mechanical  treatment,  426 
Surgical  treatment.     See  Operation. 
Suture  a  distance,  83,  91 
a  lirabeaux,  86,  87 
end-to-end,  83,  94 
inverted  V,  95 

methods  which  should  not  be  used,  95,  95 
nerves  prepared  for,  83 
oblique,  95 
primary,  86 
secondary,  86 
technic,  145,  146 
hypoglossofacial,  213.     See  Facial  nerve. 
identification,  in  nerve  suture,  142 
level  of,  144 
materials,  136 
regeneration  following,  time  of,  168 

table  showing,  170 
tissue,  reaction  from,  136,  137 
Sutured    nerve,    longitudinal    section    through, 

at  point  of  suture,  137 
Sympathectomy,     perivascular,     in     causalgia, 
449,  45°,  451 
in  synesthesialgia  and  ulnar  nerve  injury, 

450 
technic,  451 


Sympathetic  cells,  migration  of,  29 

system,    distribution   of,    to   vessels  of  lower 
extremity,  451,453 
of  upper  extremity,  451,  452 
motor  end  plates  in  muscles,  166 
role  of,  in  causalgia,  447 
Syndrome,  Horner's  in  obstetrical  paralysis  of 
brachial  plexus,  237 

Taylor's    technic    in    obstetrical    paralysis   of 

brachial  plexus,  249 
Terms  for  nerve  repair,  specific,  80 

standardization  of,  80 
Thenar  muscles,  deep  surface,   nerve    distribu- 
tion to,  326 
Thomas  and  Sever's  operation  in  neglected  cases 
of  obstetrical  brachial  plexus  paralysis,   251 
Thomas  caliper  for  paralysis  of  anterior  crural 
nerve,  428,  427 
for  sciatic  nerve  deformities,  407 
Thoracic  nerve,  long,  424 
anatomy,  424 
exposure,  425 
injury  of,  424 
deformity  in,  424 
mechanical  treatment,  425 
transverse  section  through  thoracic   seg- 
ment of  17  mm.  human  embryo,  25 
Tibial  nerve,  exposure  of,  402,  403 
injuries,  deformity  in,  409, 
mechanical  treatment,  410 
Time  of  regeneration  following  suture,  168 
table  showing,  170 
to  operate,  172 
Tinel's  sign  as  contraindication  to  operation,  166 

value  of,  167,  168,  169 
Topography,   internal,   Stoffel's  views  on,    evi- 
dence not  in  support  of,  30 
Tournicjuet,  use  of,  in  nerve  suture,  141 
Transplantation,  nerve,  67,  80,  81,  98.     See  also 
Nerve  transplantation. 
autogenous  grafts,  drawbacks  to  use  of,  roi 
autoplastic,  69 
cable  autonerve,  72,  81,  81 
in  place,  153 
in  sciatic  of  dog,  74 
26  days  after  suture,  73 
heteroplastic,  69 
homoplastic,  69 
preserved  grafts,  loi 
re-exploration,  loi 
technic,  149,  150,  r53,  336,  362,  363 
cable  transplant  in  place,  153 
Elsberg's  method,  153,  154 
Stookey's  method,  150 
value  of,  99 


INDEX 


475 


Transplantation,  nerve,  why  downgrowth   may 

not  take  place  in,  150 
Transposition  of  rausculospiral  nerve,  289   289, 
290 

of  nerve,  for  defect,  106,  35S,  289,  339,  356,  359 
of  peroneal  nerve,  405,  406 
of  ulnar  nerve,  357,  356,  359 
Triceps  muscle,  nerve  distribution  to,  267 
Tubulization,  i2r 
agar,  r2S 

arterial,  122,  123,  123,  124 
technic,  123,  123,  124 
value  of,  123 
cargile  membrane,  127 
decalcified  bone,  121  122 
fascial,  126 
fresh  vessels,  124 
gelatine,  125 
magnesium,  125 
rubber,  125 
Tumors  of  peripheral  nerves,  433 

neuroblastoma,  440,  441,  442,  443 
neurofibroma,  multiple,  434,  435 

of  sciatic  nerve,  secondary  malignant 

degeneration  of,  438 
of  ulnar  nerves,  433,  441,  442,  443 
neurosarcoma,  primary,  440 

Ulnar    and    median     nerves,     association     in 
distribution  of,  329 
communications  between,  in  hand,  326 
exposure  of,  below  pectoralis  major,  333, 

334,  335,  336 
left,  macerated  dissection  of,  31 

showing     communication     between, 

352 

nerve,  347 
anatomy,  347 
branches,  348,  349,  351 
at  wrist,  351 
in  arm,  348 
in  forearm,  348 

of  ramus   profundus  of,    to   deep   volar 
arch,  452 
cable  graft  in  place,  336,  363 


Ulnar  nerve,  course,  347 

division  of  deep  palmar  branch,  by  machine- 
gun  bullet,  365 
exposure  of,  355,  359,  361,  362,  363,  364 

at  elbow,  357,  338,  339,  359 

at  wrist,  364,  364 

in  arm,  355,  333,  334,  335,  336 

in  axilla,  355,  298,  312,  313 

in  forearm,  360 
extensive    involvement    of,    in    middle    of 

forearm,  361,  362 
funicular  anatomy,  351,  352 
injury,  deformity  in,  353 

mechanical  treatment,  353 

splint  in,  353,  354,  355 

transplantation  in,  100 
neurofibroma  of,  433,  441,  442,  443 
paralysis  of,  splint  for,  354,  355 
regeneration  following  suture,  366 
surface  projection  of,  349 
transposition  of,  338,  339,  356,  359 

with  suture  of  both  ulnar  and  median,  339 
tumor  of,  441,  442,  443 
Upper    extremity,     220.     See    also    Exircmily, 
tipper. 
radicular   type   of   brachial  plexus   paralysis, 
232.     See  also  Brachial  plexus. 

Ventral  primary  division  of  spinal  nerve,  17 
roots  of  motor  nerves  of  Polistotrema,  21 
of  spinal  nerve,  17 
formation  of,    26 

Wallerian  degeneration,  41 

Wounds,  entrance  and  exit,  possible  relation  of, 

to  course  of  missile,  158,  158,  159 
Wrist  strap  for  paralysis  of  musculocutaneous 

nerve,  310 
Wrist-drop,  276 

prevention  of,  277 

splint  for,  277,  278 

Zander  finger  machines,  330,  355 
Zone  nodule,  35 
Zone  of  reaction,  53 


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